Compressed air generating plant and method for operating same

Abstract

The invention relates to a compressed air generation device (2.9), comprising: a control and regulator (28); at least one controllable and adjustable electric motor (24); at least one air compressor (16; 18) which can be driven by the electric motor; an air inlet (8) via which ambient air (L) can be drawn into the at least one air compressor; at least one air cooler (20, 22) which is or can be connected to the output of the at least one air compressor; the input end of the air dryer is connected with the output end of the at least one air cooler; a cooling medium inlet opening (12) via which a liquid cooling medium can be fed to the at least one air cooler and further components of the compressed air generating system; and a cooling medium outlet opening (14) via which the heated cooling medium can be discharged from the compressed air generating device. The aim of the invention is to form a compressed air generating device which is as compact and inexpensive as possible during production and which is as variable as possible with respect to the cooling thereof. The air cooler (22), which is arranged as the last air cooler in front of the air dryer (40) in the direction of flow of compressed air, can be first flowed by the cooling medium as viewed in the direction of flow of the cooling medium. Furthermore, three external cooling devices (82, 120, 122) can be coupled to the compressed air generating device, which external cooling devices can be used alternately or in a superimposed manner according to cooling requirements for cooling the generated compressed air and existing components. The invention also relates to a method for operating the compressed air generating device.

Description

Technical Field

[0001] The invention relates to a compressed air generating device, which has: a control and regulator; at least one controllable and adjustable electric motor; at least one air compressor that can be driven by the electric motor; an air inlet, via which ambient air can be sucked into the at least one air compressor; at least one air cooler, which is connected or can be connected to the output of the at least one air compressor; an air dryer, the input of which is connected to the output of the at least one air cooler; a cooling medium inlet opening, via which a liquid cooling medium can be supplied to the at least one air cooler and other components of the compressed air generating device; and a cooling medium outlet opening, via which heated cooling medium can be discharged from the compressed air generating device. The invention also relates to a method for operating such a compressed air generating device. Background Art

[0002] Electrically driven compressors for generating compressed air in vehicles are already known in various embodiments and are described, for example, in DE 10 2018 139 058 A1, DE 10 2013 003 513 A1 and EP 3 516 218 B1. EP 3 331 738 B1 discloses a compressed air generating device for vehicles, which has a piston compressor and two compression stages. The cylinder chambers of the two compression stages are connected to each other via a connecting line, through which the compressed air generated in the first compression stage can be supplied to the second compression stage. During operation of the piston compressor, the ambient air pressure is increased in the first compression stage by means of the back pressure built up in the connected connecting line. An intercooler is arranged in the connecting line between the two compression stages, which is used to cool the air heated during compression in the first compression stage. Here, the pressure of the compressed air in the connecting line is reduced. Therefore, the efficiency of the second compression stage can be increased by the intercooler. Furthermore, further devices for conditioning the air used, such as further cooling devices or air drying devices, can be arranged before or after the first compression stage. It is particularly disadvantageous that the compressor is designed as a reciprocating compressor, which disadvantageously requires lubricants. Furthermore, the design of the cooling system is not described in detail.

[0003] Furthermore, DE 10 2004 051 435 B3 discloses a device for producing dry compressed air, which device has a cooling compressor for sucking in and compressing ambient air. A cooler is arranged downstream of the compressor in the direction of flow of the compressed air, which cooler is used to cool the compressed air produced. The cooling effect of the cooler is achieved by means of a fan and water droplets directed onto the surface of the cooler, where the water droplets evaporate and then draw heat from the cooler and indirectly also from the compressed air. An air dryer is arranged downstream of the cooler, which contains a drying medium, which draws air humidity from the compressed air and thereby reduces the dew point of the compressed air. The compressed air dried in this way has an air humidity of less than 35% at the output of the air dryer, which is sufficient to protect the equipment subsequently supplied with this compressed air from corrosion or freezing due to the formation of water ice.

[0004] Furthermore, DE 44 45 972 C2 discloses a compressor system for producing dry compressed air, in which an air-cooled radiator is used to cool the compressed air produced by the compressor. A water separator is arranged downstream of the radiator, by means of which water droplets formed in the compressed air by condensation when the compressed air is cooled can be removed from the compressed air. Since the compressed air is not dry enough to avoid freezing at low temperatures when it is used in a pressurized medium consumer, an air dryer is arranged downstream of the water separator in which the compressed air is further dried.

[0005] In addition, a compressed air generating device is known from DE 10 2021 121 424.6, which has not yet been published by the applicant, which has an electric motor that can drive two air compressors arranged in series. During the operation of the compressed air generating device, ambient air is sucked and compressed by means of a first air compressor. The pre-compressed compressed air is directed from there to the second air compressor via a check valve, an intercooler and a switching valve. In the second air compressor, the pre-compressed compressed air is further compressed and then transferred to the compressed air consumer via an aftercooler or another switching valve. The intercooler and the aftercooler are cooled by means of a liquid cooling medium and are used to cool the compressed air generated by the air compressor. For example, the liquid cooling medium comes from the cooling circuit of the vehicle and is first supplied to the cooling device of the electric motor in the compressed air generating device, then to the intercooler, and then finally to the cooling device of the first air compressor. From there, the cooling medium enters the aftercooler and then enters the cooling device of the second air compressor, and then the cooling medium returns to the cooling circuit of the vehicle. In this compressed air generating device, an air dryer is neither shown nor described.

[0006] Furthermore, US 2010 / 0303658 A1 discloses a water-cooled and oil-free two-stage air compressor, which has a water-cooled intercooler, which is arranged between a first air compressor and a second air compressor in terms of air conduction. The air compressed by the first air compressor is cooled by the intercooler, while the air compressed by the second air compressor is cooled by an aftercooler, the cooling water inlet of the aftercooler being hydraulically connected to the cooling water outlet of the intercooler.

[0007] Finally, DE 11 2015 006 955 T5 discloses a compressed air supply system for a locomotive and a method for operating the same, wherein the air sucked in and compressed by the compressor is cooled in an air cooler and then delivered to a first compressed air reservoir. From the first compressed air reservoir, the compressed air enters a pre-filter via a check valve closed in the return direction, the pre-filter having a dehydration valve. After liquid and aerosolized water are separated from the compressed air in the pre-filter, the compressed air enters an air dryer. A temperature sensor arranged at or directly next to the air flow inlet end of the air dryer is connected to a controller via a sensor line. The temperature sensor can measure the actual temperature of the compressed air flowing into the air dryer and provide the measured value to the controller. The controller can calculate a suitable flushing cycle time for the dehydration valve based on the saturated partial pressure of water vapor at the measured actual temperature of the compressed air, and control the manipulation of the dehydration valve to remove the water accumulated in the pre-filter.

[0008] The drying medium of the air dryers of these compressed air generating devices of this type must also be constantly cleaned of the moisture accumulated there, since the drying medium can no longer function properly when its moisture absorption capacity reaches saturation. In order to clean the air dryer of this moisture, it is known that during a so-called regeneration process, the dry compressed air generated by the compressed air generating device and stored in the compressed air reservoir is guided back through the air dryer. In this process, the dry compressed air absorbs moisture from the drying medium in the air dryer and transports this moisture outward to the surroundings of the compressed air generating device. Since these regeneration processes consume dry compressed air, which is actually required in motor vehicles, for example, for actuating brake actuators and / or air spring bellows, additional operating time of the compressor is required in order to also store sufficient compressed air for the regeneration process. However, this is associated with additional energy consumption, which, for example, increases the operating costs of the motor vehicle and, since electrical energy is generated for the electric motor, environmentally harmful CO is ultimately released into the atmosphere. 2 . Summary of the invention

[0009] Against this background, the object of the present invention is to introduce a compressed air generating device with a compressor, a liquid cooling system and an air dryer, which has a compact design and can be produced inexpensively. In addition, compared with known compressed air generating devices, the compressed air generating device should be able to achieve a lower consumption of dry compressed air when regenerating the drying medium of the air dryer. In addition, the compressed air generating device should be able to be cooled by means of one or more external cooling devices. Finally, it should be possible to determine the necessary cooling requirement and the required regenerated compressed air volume by means of a method and to control and / or regulate the compressed air generating device accordingly.

[0010] The object is achieved with a compressed air generating device having the features of claim 1. The independent method claim defines a method for operating such a compressed air generating device. Advantageous embodiments and improvements are mentioned in the respectively associated dependent claims.

[0011] Therefore, the present invention first relates to a compressed air generating device, which has: a control and regulator; at least one controllable and adjustable electric motor; at least one air compressor that can be driven by the electric motor; an air inlet end, via which ambient air can be sucked into the at least one air compressor; at least one air cooler, which is connected or can be connected to the output end of the at least one air compressor; an air dryer, whose input end is connected to the output end of the at least one air cooler; a cooling medium inlet opening, via which liquid cooling medium can be delivered to at least one air cooler and other components of the compressed air generating device; and a cooling medium discharge opening, via which the heated cooling medium can be discharged from the compressed air generating device.

[0012] In order to achieve the task associated with the device with respect to requiring as little regeneration pressure volume as possible for the drying medium regeneration process of the air dryer, it is provided that the air cooler which is arranged as the last air cooler before the air dryer in the flow direction of the compressed air can be flowed through by the coolant first, viewed in the flow direction of the coolant.

[0013] Therefore, in contrast to the previously known structural forms, the still relatively cold liquid cooling medium is first allowed to flow through an aftercooler, which is arranged immediately before the air dryer in terms of the compressed air flow direction. This cools the compressed air to the greatest extent possible, so that the air humidity contained in the compressed air is partially precipitated in the form of small water droplets before reaching the air dryer. Then, before reaching the air dryer, these water droplets are removed from the compressed air, for example, by a water separator in the aftercooler. A small amount of condensed water droplets are also brought to the air dryer by the relatively greatly cooled compressed air via a shorter compressed air line, where they are accumulated in the collection area on the input side of the air dryer and removed together with the regenerated compressed air flowing out of the air dryer during the next regeneration process. Because relatively more moisture has been removed from the compressed air before reaching the drying medium of the air dryer, less air dryers are subsequently needed to dry the compressed air. As a result, regeneration processes that require consumption of dried compressed air do not need to be performed so frequently on the air dryer.

[0014] According to a more detailed improvement scheme of the compressed air generating device just described and having the characteristics of the present invention, the compressed air generating device is equipped with the following items: a control and regulator; an electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in with the help of the first air compressor; a first air cooler constructed and arranged as an intercooler and a second air cooler constructed and arranged as an aftercooler, wherein the input end of the intercooler is pneumatically connected or connectable to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected or connectable to the input end of the aftercooler; an air dryer, wherein the input end of the air dryer is pneumatically connected to the output end of the aftercooler; and a cooling medium inlet opening, through which liquid cooling medium can be delivered to the intercooler and the aftercooler and other components of the compressed air generating device; and a cooling medium discharge opening, through which the heated cooling medium can be discharged. To achieve the above-mentioned advantages, the compressed air generating device is further characterized in that the aftercooler arranged as the last air cooler before the air dryer in the compressed air flow direction can be first flowed through by the coolant as viewed in the coolant flow direction.

[0015] In order to further cool down the compressed air to be dried in the air dryer before it enters the drying medium, according to another improved scheme of the coolant circulation loop, the cooling medium input end of the aftercooler is connected to the cooling medium inlet opening of the compressed air generating device, the cooling medium output end of the aftercooler is connected to the cooling medium input end of the intermediate cooler, the cooling medium output end of the intermediate cooler is connected to the cooling medium input end of the dryer module cooler, the cooling medium output end of the dryer module cooler is connected to the cooling medium input end of the electric motor, the cooling medium output end of the electric motor is connected to the cooling medium input end of the second air compressor, the cooling medium output end of the second air compressor is connected to the cooling medium input end of an inverter used to control and regulate the electric motor with the aid of a control and regulator, the cooling medium output end of the inverter is connected to the cooling medium input end of the first air compressor, and the cooling medium output end of the first air compressor is connected to the cooling medium delivery opening.

[0016] The dryer module cooler is constructed and arranged so that at least the components of the air dryer can be cooled by means of the dryer module cooler. It can also be provided that the multi-circuit protection valve arranged close to the air cooler is structurally integrated into the dryer module cooler or can be cooled by the dryer module cooler. The advantage of the structure is that the components of the air dryer, such as preferably its housing, are cooled so that the compressed air supplied to the air dryer can be further cooled before it enters the drying medium. As a result, the air humidity (in the last possible solution related to the device) can be condensed out of the compressed air as water and can be discharged.

[0017] In order to further improve the utilization of the compressed air generating device having the features of the present invention, it can be arranged that the cooling medium inlet opening of the compressed air generating device is hydraulically connected to the first external cooling device, a first cooling switching valve is arranged in the first cooling medium line extending from the cooling medium inlet opening to the cooling medium input end of the aftercooler, and the first cooling switching valve is constructed as a two-position two-way solenoid switching valve, which is connected to the control and regulator via control technology, and the first cooling medium line can be cut off or opened depending on its switching position by means of the first cooling switching valve.

[0018] It is thus possible, for example, not to use the first external cooling device when the cooling fluid of the first external cooling device has a temperature that is higher than the temperature of at least one of the components of the compressed air generating device. This situation occurs, for example, when a water-to-air cooler assigned to the internal combustion engine is used as the first external cooling device and the cooling water of the water-to-air cooler has a temperature that is higher than the temperature of the compressed air in the aftercooler. To this end, the cooling water temperature of the first external cooling device and the temperature of the compressed air at the input of the aftercooler are continuously measured during operation and the measured values ​​are communicated to the control and regulator. In the event of an overly high temperature, the control and regulator switches the first cooling switching valve to a switching position in which the fluid connection between the first external cooling device and the cooling medium inlet opening or the input of the aftercooler is closed. This prevents the compressed air from being heated up instead of cooled down by the overheated cooling water.

[0019] In order to further improve the cooling capacity of the compressed air generating device, it can also be additionally arranged that the output end of the first air compressor can be connected to the input end of the second external cooling device via a second cooling switching valve constructed as a two-position three-way solenoid switching valve, the second cooling switching valve is connected to the control and regulator through control technology, and the output end of the second external cooling device is connected to the input end of the second air compressor (18).

[0020] Thus, when the second cooling switching valve reaches the corresponding switching position, the compressed air generated by the first air compressor and already warm is guided to the second external cooling device and cooled there while bypassing the intercooler. The second external cooling device can be constructed as an air-to-air cooler, for example. This operating situation occurs when the coolant from the first external cooling device and flowing into the compressed air generating device is hotter than the compressed air at the aftercooler, but its coldness is still sufficient to cool other components of the compressed air generating device arranged after the two air coolers in the cooling fluid flow. In this operating situation, the compressed air accumulated at the output end of the first air compressor is cooled in the second external cooling device, while the aftercooler, the intercooler, the electric motor, the inverter and the two air compressors are cooled by the first external cooling device.

[0021] In order to further improve the cooling of the compressed air generating device, as an alternative or in addition to the cooling measures mentioned, it can be provided that the output end of the second air compressor can be connected to the input end of the third external cooling device via a third cooling switching valve constructed as a two-position three-way solenoid switching valve, the third cooling switching valve is connected to the control and regulator via control technology, and the output end of the third external cooling device is connected to the input end of the air dryer.

[0022] Thus, the compressed air from the second air compressor can also be cooled in the second external cooling device, even when the cooling fluid of the first external cooling device is too warm and cannot be used to cool the compressed air in the intercooler and aftercooler. The second external cooling device can also be designed as an air-to-air heat exchanger. The compressed air cooled in the third external cooling device is then returned to the compressed air generating device, where it enters the air dryer while bypassing the intercooler and aftercooler.

[0023] In a more detailed improvement, the compressed air generating device having the features of the present invention is equipped with: a control and regulator; an electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in by means of the first air compressor; a first air cooler constructed and arranged as an intercooler and a second air cooler constructed and arranged as an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; an air dryer, wherein the input end of the air dryer is pneumatically connected to the output end of the aftercooler; and a cooling medium inlet opening, through which liquid cooling medium can be delivered to the intercooler and the aftercooler and other components of the compressed air generating device; and a cooling medium discharge opening, through which the heated cooling medium can be discharged.

[0024] According to an improved solution of the present invention, the compressed air generating device is characterized in that the aftercooler, which is arranged as the last air cooler before the air dryer along the flow direction of the compressed air, can be first flowed through by the cooling medium from the flow direction of the cooling medium, the cooling medium inlet opening can be connected to the cooling medium output end of the first external cooling device, the output end of the first air compressor can be pneumatically connected to the input end of the intercooler via the first compressed air line DL1, a ninth compressed air line DL1.1 is connected to the first compressed air line DL1, the ninth compressed air line can be pneumatically connected to the input end of the second external cooling device, and the output end of the intercooler is connected to the input end of the second air compressor via the second compressed air line DL2. Pneumatic connection, the tenth compressed air line DL2.1 is connected to the second compressed air line DL2, the tenth compressed air line is pneumatically connected to the output end of the second external cooling device, the input end of the aftercooler can be pneumatically connected to the output end of the second air compressor via the third compressed air line DL3, the third compressed air line DL3 can be connected to the eleventh compressed air line DL3.1, the eleventh compressed air line DL3.1 is pneumatically connected to the input end of the third external cooling device, the output end of the third external cooling device is connected to the fourth compressed air line DL4 via the twelfth compressed air line DL4.1, and the fourth compressed air line DL4 connects the output end of the aftercooler with the input end of the air dryer.

[0025] Since knowing the temperature of the cooling fluid of the first external cooling device at the input of the compressed air generating device or at least at the input of the aftercooler is important for activating or deactivating the respective external cooling device, it is meaningful to arrange at least one temperature sensor in this regard.

[0026] Therefore, according to the improved scheme in this aspect, the compressed air generating device with the characteristics of the present invention is equipped with: a control and regulator; an electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in with the help of the first air compressor; a first air cooler constructed and arranged as an intercooler and a second air cooler constructed and arranged as an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; an air dryer, wherein the input end of the air dryer is pneumatically connected to the output end of the aftercooler; and a cooling medium inlet opening, through which liquid cooling medium can be delivered to the intercooler and the aftercooler and other components of the compressed air generating device; and a cooling medium discharge opening, through which the heated cooling medium can be discharged.

[0027] In the improved compressed air generating device, it is provided that at least one temperature sensor is provided, which is arranged before the cooling medium inlet and / or after the cooling medium outlet of the air cooler which is the last air cooler before the air dryer in the compressed air flow direction, in order to measure the cooling medium temperature, and the at least one temperature sensor is connected to the control and regulator via a data or sensor line. The data or sensor line can be a CAN bus line.

[0028] By arranging such temperature sensors, the control and regulation can calculate the degree to which the compressed air from the air compressor is cooled in the air cooler, and thus calculate the degree to which water is separated from the compressed air before it reaches the air dryer. With this knowledge, an optimally small volume of dry compressed air can be guided through the air dryer during the regeneration process to dry the drying medium of the air dryer. As a result, the consumption of dry compressed air is minimized and the number and / or duration of the regeneration process of the air dryer is minimized.

[0029] The design features proposed by the invention can be applied to compressed air generating devices of different configurations. Thus, such compressed air generating devices can have only one compressor stage or multiple compressor stages, which can be driven, for example, only by one electric motor or each by an electric motor. The type of construction of the compressor stage and the number of air coolers are also not fixed for the use of the invention.

[0030] According to another embodiment of the invention, the characteristics of the control and regulator are very important. Here, the compressed air generating device is equipped with: a control and regulator; an electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in by means of a first air compressor; a first air cooler that is constructed and arranged as an intercooler and a second air cooler that is constructed and arranged as an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; an air dryer, the input end of the air dryer is pneumatically connected to the output end of the aftercooler; and a cooling medium inlet opening, through which a liquid cooling medium can be supplied to the intercooler and the aftercooler and other components of the compressed air generating device; and a cooling medium outlet opening, through which the heated cooling medium can be discharged.

[0031] Here, according to the present invention, it is provided that the aftercooler, which is arranged as the last air cooler before the air dryer in the flow direction of the compressed air, can be first flowed through by the cooling medium from the flow direction of the cooling medium, there is at least one temperature sensor, the temperature sensor is connected to the control and regulator via a data or sensor line, in order to measure the cooling medium temperature, the temperature sensor is arranged before the cooling medium input end or after the cooling medium output end of the aftercooler, and the control and regulator is constructed so that in addition to the operation of the electric motor, the drying operation and regeneration operation of the air dryer and the operation of the multi-circuit protection valve can also be controlled and regulated by the control and regulator.

[0032] Since the control and regulation device is constructed and arranged according to the present invention so that the operation of the electric motor, the drying operation and the regeneration operation of the air dryer, and the operation of the multi-circuit protection valve can be controlled and regulated by the control and regulation device, a special control and regulation device for controlling and regulating the electric motor or a special control and regulation device for at least indirectly controlling and regulating the multi-circuit protection valve is not required, thereby saving production costs and structural space.

[0033] With regard to the more specific arrangement of the at least one temperature sensor, it can be provided that, in order to measure the coolant temperature, the temperature sensor is arranged upstream of the coolant inlet opening of the compressed air generating device. In this case, a temperature sensor which is already arranged on the first external cooling device of the motor vehicle can be used particularly inexpensively in order to determine the coolant temperature at the outlet of the external cooling device and forward this temperature to the control and regulation of the motor vehicle.

[0034] If the line length for transporting the cooling medium from the external cooling device to the compressed air generating device is relatively long, such an arrangement can be disadvantageous, since the cooling medium can be cooled or heated in an uncontrolled manner on the way to the cooling medium inlet of the compressed air generating device. For this reason, it can be provided that, for measuring the cooling medium temperature, the temperature sensor is arranged immediately before the cooling medium inlet of the aftercooler which is arranged as the last air cooler before the air dryer in the compressed air flow direction. This results in particularly convincing measured values.

[0035] However, it can also be provided that, for measuring the cooling medium temperature, the temperature sensor is arranged as the next following component after the cooling medium outlet of the aftercooler which is the last air cooler arranged before the air dryer in the compressed air flow direction. The temperature sensor can be arranged immediately adjacent to the cooling medium outlet of the aftercooler or, if the structural space there does not allow this, can be arranged at the next possible position after the cooling medium outlet of the aftercooler in the cooling medium flow direction.

[0036] It can also be provided that a temperature sensor connected to the control and regulator via signal technology is arranged at the cooling medium input and cooling medium output of the aftercooler. With the temperature values ​​measured by the two temperature sensors, a temperature difference can be determined in the control and regulator, which is a measure of the temperature drop of the compressed air in the aftercooler. Based on this, it can at least be estimated how much water condenses from the compressed air when it flows through the aftercooler. If necessary, a further temperature sensor is required for this purpose, with which the compressed air temperature at the compressed air input of the aftercooler can be measured.

[0037] According to another improvement of the subject matter of the present invention, it can be provided that at least one electric motor, an inverter that influences the operation of the electric motor, two air compressors, an intercooler, an aftercooler, an air dryer, a multi-circuit protection valve that pneumatically connects the output end of the air dryer to at least one external compressed air reservoir and an external compressed air consumer, and a silencer are arranged to act in a coordinated manner but are separate from each other.

[0038] Alternatively, it can be provided that at least one electric motor, an inverter that influences the operation of the electric motor, two air compressors, an intercooler, an aftercooler, an air dryer, a multi-circuit protection valve that pneumatically connects the output of the air dryer to at least one external compressed air reservoir and an external compressed air consumer, and a silencer are arranged in or on a common housing.

[0039] In both of the described constructional variants, the mentioned device components are connected to one another in a suitable manner via the described electrical, pneumatic and hydraulic connecting lines which are arranged in the housing, if necessary. This allows the compressed air generating device to be constructed extremely compactly, to be easy to assemble during its manufacture and to be easily fastened to a motor vehicle, for example a commercial vehicle.

[0040] In this regard, it can also be provided that the control and regulator is arranged separately or in or on the housing of the compressed air generating device, the control and regulator is connected to the inverter via a first control line for controlling the electric motor, the control and regulator is connected to the regeneration switching valve constructed as a first two-position three-way solenoid switching valve via a second control line, the first two-position three-way solenoid switching valve is used to open or close the regeneration line that pneumatically connects the compressed air reservoir and the air dryer at least indirectly, and the control and regulator is connected to the multi-circuit protection valve via a sensor line.

[0041] By additionally integrating the control and regulator, the first two-position three-way electromagnetic switching valve or the regeneration switching valve, and the associated control lines and regeneration lines into the housing of the compressed air generating device, the housing contains other components associated with the compressed air generating device, and these other components make the entire system easier to operate and easier to connect to the motor vehicle. Therefore, when one of these components fails, the compressed air generating device can be easily removed from the commercial vehicle as a whole and sent to a maintenance center, and a new compressed air generating device can be quickly and conveniently assembled on the motor vehicle. Since the compressed air generating device is an indispensable device for the operation of commercial vehicles, the above method avoids long-term maintenance and allows the commercial vehicle to be put into use quickly.

[0042] In order to further improve the maintainability of the compressed air generating device and to enable rapid maintenance, according to another improvement of the compressed air generating device, it can be provided that the compressed air generating device is constructed from a plurality of modules, which are arranged together with the associated pneumatic, hydraulic and electrical lines in or on a common housing.

[0043] Therefore, it can be provided that a compressor module, a compressed air cooling module, a dryer module and a silencer module, together with the associated pneumatic, hydraulic and electrical lines, are arranged in or on the housing of a compressed air generating device, wherein the compressor module has an electric motor, an inverter, two air compressors and a control and regulator, wherein the compressed air cooling module includes an intercooler and an aftercooler, wherein the dryer module includes an air dryer and a multi-circuit protection valve, wherein the silencer module has a silencer with silencer material, and wherein the silencer module has at least one regeneration air outlet opening, which is used to discharge the regeneration compressed air into the surrounding environment.

[0044] The silencer material is designed so that it can absorb the water droplets separated from the air dryer and can also be guided together with the splash water injected into the silencer to the water outlet of the silencer module. In certain applications, the integration of individual silencer modules can be omitted.

[0045] Another variant of the compressed air generating device having the features of the present invention is equipped with at least one electric motor, by which at least one air compressor can be driven, and the compressed air generating device has an air inlet end, through which ambient air can be sucked in by means of the air compressor. The compressed air generating device has at least one air cooler, in which the air squeezed by the air compressor can be cooled. In addition, there is an air dryer, the input end of the air dryer is pneumatically connected to the output end of the at least one air cooler. In addition, a cooling medium inlet opening is also constructed, through which a liquid cooling medium can be conveyed to the air cooler. In addition, there is a cooling medium outlet opening, through which the heated cooling medium can be discharged.

[0046] The compressed air generating device is characterized in that the silencer has at least one regeneration air outlet opening, which is used to discharge the regeneration exhaust gas guided through the silencer into the surrounding environment. When the drying medium of the air dryer is not regenerated, the at least one regeneration air outlet opening is used to draw ambient air to the air inlet end of at least one air compressor, and the ambient air drawn through the silencer can be guided to the at least one air compressor downstream through the suction line after the silencer.

[0047] The improved scheme of the compressed air generating device derived from this has the following items: at least one electric motor; two air compressors driven by the electric motor and acting in sequence; an air inlet end, through which ambient air can be sucked in with the help of the first air compressor; and an intercooler and an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; in addition, there is also an air dryer, the input end of the air dryer is connected to the output end of the aftercooler; and a cooling medium inlet opening, through which liquid cooling medium can be delivered to the intercooler and the aftercooler; and a cooling medium discharge opening, through which the heated cooling medium can be discharged.

[0048] The improved compressed air generating device is also characterized in that the silencer has at least one regeneration air outlet opening for discharging the regeneration exhaust gas guided through the silencer into the surrounding environment, and when the drying medium of the air dryer is not regenerated, the at least one regeneration air outlet opening is used to draw ambient air to the air inlet end of the first air compressor, and the ambient air drawn through the silencer can be guided to the first air compressor downstream after the silencer through a suction line.

[0049] In order to prevent the silencer from being exposed to undesired contamination or severe splashing of water via the combined inlet and outlet for the ambient air to be sucked in and via the discharge of the moisture-laden regeneration compressed air, according to a further development of the compressed air generating device, a separator for separating water and particles is arranged upstream of the silencer or in the silencer, the separator being designed and arranged in such a way that the ambient air sucked in through at least one regeneration air outlet opening, which also serves as an air inlet, can be freed of entrained water droplets and particles. Such a separator can be designed, for example, as a cyclone separator, in which the sucked-in ambient air is guided in a circular or spiral motion.

[0050] Another compressed air generating device with the features of the present invention also has at least one electric motor, which can drive at least one air compressor. In addition, there is an air inlet end, through which ambient air can be sucked by means of a first air compressor. In addition, there is at least one air cooler, in which the air squeezed by the air compressor can be cooled. An air dryer is also arranged, and the input end of the air dryer is pneumatically connected to the output end of the at least one air cooler. In addition, a cooling medium inlet opening is also constructed on the compressed air generating device, through which a liquid cooling medium can be delivered to the air cooler from a first external cooling device. The heated cooling medium can be returned to the first external cooling device via the cooling medium delivery opening that also exists. In addition, a multi-circuit protection valve is also arranged, which pneumatically connects the output end of the air dryer to at least one external compressed air reservoir and an external compressed air consumer. In addition, there is a control and regulator, which is connected to the multi-circuit protection valve and the sensor arranged there via at least one sensor line.

[0051] In order to make the compressed air generating device independent of a specific, possibly vehicle-specific multi-circuit protection valve, according to the improvement scheme discussed here, the multi-circuit protection valve can be separated from other components of the compressed air generating device and can be operated away from these components. The control and regulator and the multi-circuit protection valve have electrical connecting mechanisms, which are connected to each other in a detachable manner via at least one flexible electrical line, and the multi-circuit protection valve has a pneumatic connecting mechanism, which is at least indirectly connected to the output end of the air dryer in a detachable manner via at least one flexible pneumatic line.

[0052] The present invention also relates to a more detailed improvement of a variant of the above-mentioned compressed air generating device, which comprises: at least one electric motor, two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in by means of a first air compressor; an intercooler and an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; an air dryer, wherein the input end of the air dryer is connected to the output end of the aftercooler; a cooling medium inlet opening, through which liquid cooling medium can be conveyed to the intercooler and the aftercooler; a cooling medium discharge opening, through which heated cooling medium can be discharged; a multi-circuit protection valve, which pneumatically connects the output end of the air dryer to at least one external compressed air reservoir and an external compressed air consumer; and a control and regulator, which is connected to the multi-circuit protection valve and the sensor arranged there via a sensor line.

[0053] In this variant of the compressed air generating device, the present invention also provides that the multi-circuit protection valve can be separated from other components of the compressed air generating device and can operate away from these components, the control and regulator and the multi-circuit protection valve have electrical connecting mechanisms, which are connected to each other in a detachable manner via at least one flexible electrical sensor line, and the multi-circuit protection valve has a pneumatic connecting mechanism, which is at least indirectly connected to the output end of the air dryer in a detachable manner via at least one flexible pneumatic line.

[0054] In another design scheme of the above-mentioned two compressed air generating devices, it is provided that a dryer module with an air dryer has at least one electrical socket and at least one pneumatic socket, the electrical socket of the dryer module is connected to the electrical socket on the control and regulator via a sensor line, the electrical plug of the electrical connecting line is detachably inserted into the electrical socket of the dryer module, the electrical connecting line has a second plug that can be detachably inserted into the electrical socket of the multi-circuit protection valve, the pneumatic socket of the dryer module is pneumatically connected to a fifth compressed air line, the dried compressed air from the air dryer can be guided through the fifth compressed air line, the plug of the pneumatic connecting line can be detachably inserted into the pneumatic socket of the dryer module, and the pneumatic connecting line has a second plug that can be detachably inserted into the pneumatic socket of the multi-circuit protection valve.

[0055] In order to make the compressed air generating device with the features of the present invention particularly compact, that is, to save structural space, the compressed air generating device has at least one electric motor, which can drive at least one air compressor. The at least one air compressor can draw ambient air through the air inlet end. In addition, there is at least one air cooler, in which the air squeezed by the at least one air compressor can be cooled. In addition, an air dryer is arranged, and the compressed air cooled by the air cooler can be dried by the air dryer. In addition, the compressed air generating device also has a cooling medium inlet opening, through which a liquid cooling medium can be conveyed to the air cooler. The heated cooling medium can be discharged through a cooling medium discharge opening of the same structure.

[0056] Now, the compressed air generating device is improved in such a way that the control and regulator are an integrated component of the inverter. As a result, the compressor module described above is particularly compact, in which at least one electric motor, an inverter, two air compressors and an intercooler assigned to these air compressors are arranged. Therefore, the control and regulator are structurally accommodated in the housing of the inverter, or form a structural unit with the inverter, so that the control line from the control and regulator to the electronic components of the inverter is also optimally short. Of course, the design described can also be reversed in structure, that is, the inverter is an integrated component of the control and regulator.

[0057] In another design scheme of the integration of the control and regulator, the compressed air generating device can also be constructed as follows: at least one electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in by means of the first air compressor; an intercooler and an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; and further having an air dryer, the input end of the air dryer is connected to the output end of the aftercooler; a cooling medium inlet opening, through which liquid cooling medium can be supplied to the intercooler and the aftercooler; a cooling medium discharge opening, through which heated cooling medium can be discharged; a multi-circuit protection valve, which pneumatically connects the output end of the air dryer to at least one external compressed air reservoir and an external compressed air consumer; and a control and regulator, which is connected to the multi-circuit protection valve and the sensor arranged there via at least one sensor line. In this development of the compressed air generating device, it is provided that the control and regulation system having the mentioned advantages is also an integrated component of the inverter.

[0058] However, control and regulators can also be integrated into multi-circuit protection valves or vice versa. According to the improved scheme, the compressed air generating device discussed here has: at least one electric motor; two air compressors that can be driven by the electric motor and act in sequence; an air inlet end, through which ambient air can be sucked in by means of the first air compressor; an intercooler and an aftercooler, wherein the input end of the intercooler is pneumatically connected to the output end of the first air compressor, wherein the output end of the intercooler is pneumatically connected to the input end of the second air compressor, and wherein the output end of the second air compressor is pneumatically connected to the input end of the aftercooler; and an air dryer, wherein the input end of the air dryer is connected to the output end of the aftercooler; and a cooling medium inlet opening, through which liquid cooling medium can be supplied to the intercooler and the aftercooler; a cooling medium discharge opening, through which the heated cooling medium can be discharged; a multi-circuit protection valve, which pneumatically connects the output end of the air dryer to at least one external compressed air reservoir and an external compressed air consumer; and a control and regulator, which is connected to the multi-circuit protection valve and the sensor arranged there via at least one sensor line. According to this development, it is provided that the control and regulator is an integrated component of the multi-circuit protection valve.

[0059] Alternatively, it can be provided that in the compressed air generating device just described (the features of which are not repeated here), the control and regulation device is an integrated component of the preferably central vehicle control device. This saves additional costs and installation space for the control and regulation device of the device itself, but sensor lines and control lines to the central vehicle control device of the vehicle must be present for operating the compressed air generating device by means of the control and regulation device.

[0060] The compressed air generating plant having the features of the invention is designed structurally in such a way that the air dryer can be operated optimally both for drying compressed air and for regeneration, ie for dehumidifying the drying medium. To this end (which will be described in detail in conjunction with an embodiment), it is preferably provided that the output end of the air dryer is connected to a fifth compressed air line via a first check valve closed in the direction of the air dryer, the fifth compressed air line leads to at least one compressed air reservoir and to a compressed air consumer via the multi-circuit protection valve, the regeneration compressed air input end of the air dryer is connected to the output end of a first regeneration switching valve constructed as a 3 / 2-way solenoid switching valve via a second check valve opened in the direction of the regeneration compressed air input end, a throttle element and a first line branch, the input end of the first 3 / 2-way solenoid switching valve is connected to the fifth compressed air line via a regeneration line, when the first 3 / 2-way solenoid switching valve is actuated, dry compressed air can be supplied to the air dryer as regeneration compressed air via the 3 / 2-way solenoid switching valve, the first line branch, the throttle element and the first check valve, and also when the first 3 / 2-way solenoid switching valve is actuated, the regeneration compressed air can be supplied to the pneumatic control input end of the pneumatically actuable 2 / 2-way switching valve assigned to the regeneration air output end of the air dryer via the second line branch.

[0061] The regeneration process at the air dryer is therefore initiated by the control and regulator and is pneumatically controlled, primarily, by means of a first 3 / 2-way electromagnetic switching valve or regeneration switching valve. By means of the first 3 / 2-way electromagnetic switching valve, the dried regeneration compressed air is directed to the air dryer and at the same time the pneumatic control pressure is directed to the control pressure input of the pneumatic 2 / 2-way switching valve for opening the regeneration air output of the air dryer. The control pressure is generated by a small portion of the regeneration compressed air that is largely directed from the compressed air reservoir into the air dryer for drying the drying medium there.

[0062] Another improvement provides that a pressure-controlled two-position two-way switching valve is assigned to the collection area of ​​the air dryer, wherein the pneumatic control input of the two-position two-way switching valve is connected to the output of the first two-position three-way electromagnetic switching valve via a second line branch. The two-position two-way switching valve is configured so that it is closed when not operated. In addition, the pressure-controlled two-position two-way switching valve can be switched from its closed position to its open position by means of regeneration compressed air supplied to the air dryer and supplied via the second line branch. When the pressure-controlled two-position two-way switching valve is open, the dry regeneration compressed air can be guided through the drying medium of the air dryer in the regeneration compressed air flow. After flowing through the drying medium, the regeneration compressed air can be guided to the collection area of ​​the air dryer and can entrain the accumulated condensate there, and can be removed from the air dryer via at least one regeneration air outlet on the air dryer.

[0063] In addition, the compressed air generating device preferably also has another temperature sensor that can measure the ambient temperature. This other temperature sensor is also connected to the control and regulator via a data or sensor line. If a data line is used, this data line can be a CAN bus line.

[0064] The invention also relates to a method for operating a compressed air generating device having the above-described features. According to the method, air compressed by means of at least one air compressor is cooled in at least one air cooler. The cooled compressed air is subsequently fed to an air dryer and dried there in order to then be conducted to a compressed air consumer and / or to at least one compressed air reservoir. During the regeneration operation of the compressed air generating device, in order to regenerate the drying medium arranged in the air dryer, a certain amount of dry compressed air of the regeneration compressed air volume required for this purpose is conducted through the drying medium and subsequently discharged to the surrounding environment.

[0065] It is provided here that the volume of regeneration compressed air required for regenerating the drying medium is calculated at least as a function of the temperature of the cooling medium before and / or after the air cooler through which it flows, that is, the last air cooler arranged before the air dryer, and that the dry compressed air of the regeneration compressed air volume determined in this way is subsequently guided through the air dryer.

[0066] Since the amount of water that the compressed air carries with it as air humidity on its way to the air dryer after passing through the last air cooler is related to the compressed air temperature there, it would seem disadvantageous not to initially determine the volume of regeneration compressed air required for the regeneration operation of the compressed air generating device based on a direct measurement of the temperature of the compressed air flow before the air dryer.

[0067] However, the approach presented here has the advantage that no additional temperature sensors are required to obtain conclusions about the temperature of the compressed air before it reaches the air dryer and how much water it carries in the form of air humidity. As stated above, today, in every motor vehicle with a liquid cooling system, the temperature of the cooling medium is measured by means of a temperature sensor after leaving the cooler of the liquid cooling system, and the measured value of the cooling medium temperature is used for various purposes in the motor vehicle, for example via a CAN data bus. Knowing the temperature of the cooling medium immediately after leaving the vehicle cooler or the temperature immediately before the air cooler in question, it is possible to indirectly infer the temperature of the compressed air after leaving the air cooler, without requiring a special temperature sensor for this purpose.

[0068] The operation of the compressed air generating system and in particular the supply of the cooling medium can then be regulated in such a way that the cooling effect of the last air cooler before the air dryer is maximized. As a result, the compressed air is cooled to the maximum extent before the air dryer, so that the compressed air has only a relatively small amount of moisture that is taken on by the air dryer. As a result, the drying medium of the air dryer does not need to be regenerated as frequently and with a smaller volume of regeneration compressed air.

[0069] In a further embodiment of the method, it is provided that the cooling medium temperature before the cooling medium inlet opening of the compressed air generating device is measured by means of a first temperature sensor, and that the regeneration compressed air volume required for drying the drying medium in the air dryer is guided through the air dryer in a controlled and / or regulated manner during a subsequent regeneration process as a function of the measured cooling medium temperature.

[0070] Alternatively to this, it can be provided that the cooling medium temperature upstream of the cooling medium inlet of an air cooler immediately upstream of the last air cooler arranged in the direction of compressed air flow in this list is measured with the aid of a second temperature sensor, and that the regeneration compressed air volume required for drying the drying medium in the air dryer is directed through the air dryer in a controlled and / or regulated manner during a subsequent regeneration process depending on the measured cooling medium temperature.

[0071] Furthermore, it can be provided that the cooling medium temperature after the cooling medium output of the air cooler which is the last air cooler arranged before the air dryer in the compressed air flow direction is measured by means of a third temperature sensor and that the regeneration compressed air volume required for drying the drying medium in the air dryer is directed through the air dryer in a controlled and / or regulated manner during a subsequent regeneration process depending on the measured cooling medium temperature.

[0072] According to a further specialization of the method, the following method steps can be provided: a) sucking in ambient air by means of a first air compressor, b) pre-compressing the sucked ambient air to a first air pressure value in a first air compressor, c) Cooling the intercooler with liquid cooling medium, d) cooling the pre-compressed compressed air in an intercooler, e) further compressing the compressed air to a second higher pressure value by means of a second air compressor, f) cooling the aftercooler with a liquid cooling medium, wherein the aftercooler, viewed in the flow direction of the cooling medium, is the first air cooler to be hydraulically reached by the cooling medium, g) cooling the compressed air further compressed in the second air compressor in an aftercooler, h) Drying the cooled compressed air in an air dryer, i) forwarding the cooled and dried compressed air to a compressed air consumer and / or to at least one compressed air reservoir.

[0073] These method steps clearly show that the compressed air leaving the second air compressor is cooled to the extent that a freshly supplied liquid cooling medium can achieve when flowing through the aftercooler. For this purpose, it is provided that the liquid cooling medium is not first guided to a cooling device or an intercooler of the electric motor, as in the compressed air generation device according to DE 10 2039 139 424.6, in order to cool these cooling devices during operation. On the contrary, in the compressed air generation device presented here, the cooling medium is first guided to the aftercooler in order to cool the cooling medium and thus also cool the compressed air as much as possible. It is thus possible according to the method to cool the generated compressed air to a great extent before it reaches the air dryer, so that as much moisture as possible is separated from the compressed air and guided out.

[0074] In order to also cool further components of the compressed air generating system with a liquid cooling medium, the following further method steps are provided in addition to the method just mentioned: j) Transfer the liquid cooling medium from the aftercooler to the intercooler, k) Transferring the liquid cooling medium from the intercooler to the cooling device of the electric motor, l) transferring the liquid cooling medium from the cooling device of the electric motor to the cooling device of the second air compressor, m) transferring the liquid cooling medium from the cooling device of the second air compressor to the cooling device of the inverter, n) transferring the liquid cooling medium from the cooling device of the inverter to the cooling device of the first air compressor, o) Transferring the liquid cooling medium from the cooling device of the first air compressor to the external cooling device.

[0075] In addition to the way in which the cooling medium is conducted (especially first to the aftercooler) and the way in which the compressed air is conducted in the compressed air generation system, the way in which the drying medium of the air dryer is regenerated is also particularly important. In this regeneration, the temporarily stored dry compressed air is passed in the opposite direction through the drying medium, which has removed moisture from the compressed air supplied during the previous drying process and whose dryness has now been greatly reduced. In this process, the compressed air will take up moisture from the drying medium and flow out of the air dryer into the surroundings with it. The frequency with which such regeneration processes need to be carried out and the compressed air volume required for these regeneration processes influence the demand for compressed air to be generated by the compressed air generation system during vehicle operation. Since water has already been separated from the compressed air in the aftercooler when the compressed air is cooled as described above, this water enters the inlet region of the air dryer together with the compressed air conducted to the air dryer in the form of a water film or water droplets, from which this water will be discharged into the surroundings before reaching the drying medium.

[0076] However, it can also be conveniently provided that the time interval between two regeneration operations for drying the drying medium of the air dryer is controlled and / or regulated as a function of the temperature of the cooling medium at the outlet of the external cooling device or at the inlet of the aftercooler.

[0077] Since the temperature of the cooling medium plays a decisive role in how much water has condensed at the aftercooler from the compressed air supplied to the aftercooler, a relatively low cooling medium temperature will result in relatively more water being separated from the compressed air at the aftercooler and discharged therefrom. As a result, the drying medium of the air dryer is less stressed than in the case of a relatively high cooling medium temperature, so that the regeneration compressed air volume can be smaller or, for example, the time interval between two regeneration processes can be longer.

[0078] When performing a regeneration process of the type described, the vehicle's ambient temperature must also be taken into account, since the compressed air stored in the compressed air reservoir will, after a period of time, take on the ambient temperature via the walls of the compressed air reservoir. Since the compressed air stored in this compressed air reservoir is also used to regenerate the drying medium in the air dryer, and the compressed air temperature also determines the water storage capacity of the regeneration compressed air, knowing the ambient temperature is important for determining the necessary regeneration compressed air volume.

[0079] Thus, when previously dried and temporarily stored compressed air is conducted as regeneration compressed air in the opposite direction through the air dryer for regenerating the drying medium in the air dryer, it can be provided that the time interval between two regeneration processes for drying the drying medium of the air dryer is controlled and / or regulated during subsequent regeneration processes as a function of the average ambient temperature. The average value of the ambient temperature can be determined within a predetermined period of time.

[0080] Likewise, it can be provided in the method that the respectively required regeneration compressed air volume for drying the drying medium is also controlled and / or regulated during the subsequent regeneration process in a manner dependent on the ambient temperature.

[0081] For example, if the ambient temperature and the coolant temperature change rapidly due to the current driving situation and / or rapidly changing environmental conditions, it can be provided that the regeneration compressed air volume required for drying the drying medium or the duration and / or frequency of the regeneration process respectively is controlled and regulated also as a function of the difference between the ambient temperature and the coolant temperature.

[0082] In the case of unregulated control of the regeneration of the drying medium of the air dryer, according to a further improvement of the described method for operating a compressed air generating device, it is provided that a maximum high temperature value of the cooling medium to be expected during operation of the compressed air generating device is determined, this value of the cooling medium temperature is used as the basis for determining the maximum regeneration compressed air volume, and the associated regeneration process for the drying medium is carried out using this maximum regeneration compressed air volume.

[0083] In order to cool the compressed air as much as possible before it is dried in the drying medium of the air dryer, it can be provided in an improved version of the method described above that the cooling medium from the cooling medium output end of the intercooler is not transported directly to the cooling medium input end of the electric motor, but via a dryer module cooler, and the dryer module cooler cools at least the components of the air dryer.

[0084] As an alternative or in addition to the method variant just mentioned, it can be provided that the temperature of the cooling medium is measured at the output of the first external cooling device or at the input of the aftercooler, and when the temperature of the cooling medium determined reaches or exceeds a first high limit value specified in advance, the compressed air from the output of the first air compressor is no longer transported via the intercooler, but via the second external cooling device to the input of the second air compressor. For example, the first limit value of the temperature can be 80 degrees Celsius.

[0085] This method variant is particularly used when the temperature of the cooling medium from the first external cooling device is higher than the temperature of the compressed air at the pneumatic input of the intercooler and / or at the pneumatic input of the aftercooler, because the compressed air cannot be cooled by means of these air coolers. In this case, the compressed air is guided from the output of the first air compressor to the input of the second external cooling device, where the compressed air is cooled. After flowing through the second external cooling device, the cooled compressed air is guided to the input of the second air compressor, where it is exposed to a higher air pressure. In the continuation of the method, the compressed air can then be guided via the aftercooler, which is switched to a passive aftercooler in terms of its cooling capacity in this case, and from there to the air dryer in the usual way.

[0086] Furthermore, if the temperature of the liquid cooling medium of the first external cooling device is too high to cool the compressed air in the intercooler and the aftercooler, and the cooling power of the second external cooling device is insufficient to bring the compressed air to a low temperature so that a relatively large portion of the air humidity in the compressed air condenses into water droplets that can be transported away before the air dryer, a third external cooling device can be used. To achieve this in the described operating conditions of the compressed air generating device, it is provided that the temperature of the cooling medium is measured at the outlet of the first external cooling device or at the inlet of the aftercooler, and when the temperature of the cooling medium reaches or exceeds a predefined second limit value greater than the first limit value, the compressed air from the outlet of the first air compressor is conveyed to the inlet of the second air compressor not via the intercooler but via the second external cooling device, and then additionally the compressed air from the outlet of the second air compressor is conveyed to the outlet of the aftercooler or the inlet of the air dryer not via the aftercooler via the third external cooling device.

[0087] In the latter two methods, it must be ensured that the other components of the compressed air generating device to be cooled, namely the electric motor, the inverter and the two air compressors, are cooled in another way by the liquid cooling medium of the first external cooling device, provided that the temperature of the cooling medium is suitable for this. This means that the liquid cooling medium of the first external cooling device is guided through the cooling devices of the electric motor, the inverter and the two air compressors even when no compressed air is guided through the intercooler and / or the aftercooler. This can be achieved by means of a further cooling medium line and at least one further appropriately arranged switching valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to better understand the present invention, the present specification is accompanied by drawings with multiple embodiments. Among them:

[0089] Figure 1A schematic diagram of a compressed air generating device that can be electrically driven and cooled by an external cooling device is shown, the compressed air generating device having two air compressors, an intercooler, an aftercooler, an air dryer, a multi-circuit protection valve, a dryer module cooler and a silencer;

[0090] Figure 2 Shown according to Figure 1 A similar compressed air generating device, to which three external cooling devices can be connected by means of formed interfaces and internal line guides;

[0091] Figure 3 Shown according to Figure 2 A detailed schematic diagram of the internal line guide and interface of the compressed air generating device;

[0092] Figure 4 Shown according to Figure 1 A similar compressed air generating device in which ambient air can be drawn through a silencer by a first air compressor;

[0093] Figure 5 Shown according to Figure 4 A similar compressed air generating device, but with a different arrangement of the cooling medium temperature sensor and with a water and particle filter arranged in the silencer, through which the sucked-in ambient air can be conducted to the first air compressor;

[0094] Figure 6 Shown according to Figures 1 to 5 A similar compressed air generating device, in which the multi-circuit protection valve is arranged outside the dryer module and can be operated outside the dryer module;

[0095] Figure 7 Shown according to Figure 6 A similar compressed air generating device, in which the multi-circuit protection valve is arranged outside the compressed air generating device and is connected to the electrical control and regulator or the dryer module via flexible electrical and pneumatic lines; and

[0096] Figure 8 Shown according to Figure 5 A similar compressed air production device, but in which ambient air for the first air compressor can be drawn through an air intake in the compressor module. DETAILED DESCRIPTION

[0097] In these figures, pneumatic lines for conveying air or compressed air are represented by solid lines, hydraulic lines for conveying liquid cooling medium are represented by dashed lines, and electrical lines are represented by dotted lines.

[0098] The following will first refer to Figure 8 The basic structure of the compressed air generating apparatus having the features of the present invention is explained.

[0099] In this embodiment, Figure 8 The compressed air generating device 2.7 shown in the figure has a closed but also openable housing 6, in which the components of the compressed air generating device 2.7 are combined in modules, which are arranged one after the other. Thus, the compressor 4 is arranged in a compressor module 90, which has an electric motor 24 with two drive shafts 30, 32, an inverter 26, a first air compressor 16, a second air compressor 18 and a control and regulator 28.

[0100] Furthermore, a compressed air cooling module 92 is arranged in the housing 6, which has an intercooler 20 and an aftercooler 22. The two air coolers 20, 22 are used to cool the compressed air generated by the compressor 4. For this purpose, the two air coolers 20, 22 use a liquid cooling medium delivered by the first external cooling device 82. In the example described here, the first external cooling device 82 is a cooling device of a commercial vehicle with a suitable heat exchanger (not shown here). The aftercooler 22 is arranged so that it is the first component to be supplied with cold liquid cooling medium by the external cooling device 82. In addition, the aftercooler 22 is the last air cooler arranged in the compressed air flow from the second air compressor 18 before the air dryer 40.

[0101] At least one temperature sensor is arranged to measure the temperature of the cooling medium, which is connected to the control and regulator 28 via a data or sensor line 59. The temperature sensor 73 can be arranged at the cooling medium output of the first external cooling device 82. As an alternative to this, a temperature sensor 73' can be arranged at the cooling medium input of the aftercooler 22, or a temperature sensor 73'' can be arranged at the cooling medium output of the aftercooler 22. The cheapest arrangement of such a temperature sensor 73 is undoubtedly to arrange it at the cooling medium output of the external cooling device 82.

[0102] If temperature sensors 73', 73" are arranged at the cooling medium input end and the cooling medium output end of the aftercooler 22, respectively, the temperature reduction of the cooling medium when flowing through the aftercooler 22 can be determined by the difference between the measured values ​​provided by the two temperature sensors 73', 73", and thus the cooling effect of the compressed air to be cooled can be known. For example, if the compressed air temperature at the compressed air input end of the aftercooler 22 and the compressed air volume flow rate per second passing through the aftercooler 22 are additionally known, the compressed air temperature reduction that occurs due to the transfer of the energy to the cooling medium of the aftercooler 22 can be known. Based on the compressed air temperature reduction that can be determined in this way, it can be confirmed what kind of dew point deviation of the compressed air occurs and how much water W is separated from the compressed air at the aftercooler 22 per second.

[0103] Subsequently, a dryer module 94 is placed in the housing 6, in which the air dryer 40 and the multi-circuit protection valve 50 are arranged. The air dryer 40 contains a drying medium 41, by which air humidity can be extracted from the compressed air guided to the air dryer 40. When the dried compressed air is guided through the air dryer 40 in the opposite direction during the regeneration process, the drying medium 41 can release this moisture to the dried air again.

[0104] As will be explained further, the multi-circuit protection valve 50 does not have to be a component of the dryer module 94, but it is advantageous to arrange it in the common housing 6. What can be achieved by means of the multi-circuit protection valve 50 is that the compressed air released from the air dryer 40 is selectively released to different compressed air consumers 50, 51 via compressed air lines DL6, DL7 and / or to at least one compressed air reservoir 45 via compressed air line DL8. In addition, it should be mentioned that the sixth compressed air line DL6 and the seventh compressed air line DL7 leading to the compressed air consumers 50, 51 can also be connected to other compressed air reservoirs halfway. Similarly, at least one other compressed air consumer not shown is connected to the compressed air reservoir 45 shown. The first two-position three-way electromagnetic switching valve 72 arranged in the dryer module 94 enables the air dryer 40 to be switched to air drying operation or regeneration operation, wherein, in regeneration operation, the drying medium 41 of the air dryer 40 can be dried. This point will be discussed further below. The first two-position three-way electromagnetic switching valve 72 is hereinafter also referred to as a regeneration switching valve.

[0105] Finally, the compressed air generating device 2.7 has a silencer module 96, which is constructed here as a silencer 43 containing a silencer material 44, which is only partially shown in the figure in order to better identify other details. The silencer material 44 can suppress the noise emission generated when the regeneration exhaust gas AL carrying moisture is discharged from the air dryer 40 during the regeneration process. The silencer module 96 has a plurality of regeneration air outlet openings, only one regeneration air outlet opening 34 is shown in the figure, and the regeneration exhaust gas AL can be released into the surrounding environment through the regeneration air outlet opening. In addition, the silencer module 96 or the silencer 43 has at least one water outlet opening 36 at its lowest part, and the water droplets separated from the compressed air in the air dryer 40 during normal operation and / or the splashing water that penetrates through the regeneration air outlet opening 34 can be removed through the water outlet opening via the water separation path 80 formed by itself. The silencer module 96, the silencer 43 or the silencer material 44 can be fastened to the housing 6 in a way that can be easily replaced.

[0106] The components of the four modules 90 , 92 , 94 , 96 are connected to one another as required via pneumatic, hydraulic and electrical lines, which will be discussed in detail when describing the method for operating a compressed air generating system 2 . 7 .

[0107] The function and interaction of the components of the compressed air generating device 2.7 are as follows:

[0108] The operation of the compressor 4 is controlled and regulated by means of the control and regulation device 28 described above. The control and regulation device 28 is connected via a low-voltage line 57 to a low-voltage source (not shown in detail), to the data or sensor line 59 described above of a vehicle-specific data communication system (such as a CAN bus), and to at least one control line 54. The control line 54 leads to the inverter 26, which influences the operation of the electric motor 24 and is connected via a high-voltage line 58 to a voltage source (not shown in detail).

[0109] In order to start and operate the electric motor 24 of the compressor 4, the electric motor is driven in a desired manner by means of a controller and regulator 28 and an inverter 26. As a result, the two drive shafts 30, 32 of the electric motor 24 are caused to rotate. The first drive shaft 30 is connected to the first air compressor 16 in a driving manner, and the second drive shaft 32 is connected to the second air compressor 18 in a driving manner. The two air compressors 16, 18 are scroll compressors known per se. The first air compressor 16 is connected to the ambient air L on the input side via the air inlet opening 8 in the housing 6. When the first air compressor 16 is in operation, the first air compressor sucks the ambient air L via the suction line DL and compresses the ambient air into compressed air with a first air pressure value.

[0110] The first air compressor 16 is pneumatically connected to the input of the second air compressor 18 on the output side via the first compressed air line DL1, the intercooler 20 and then via the second compressed air line DL2. The intercooler 20 cools the pre-pressed compressed air, wherein water is condensed and discharged if necessary. In the second air compressor 18, the cooled compressed air is then further compressed to the desired higher second air pressure value and then supplied to the above-mentioned aftercooler 22 via the third compressed air line DL3. The compressed air is further cooled in the aftercooler 22. Here, air humidity is condensed from the compressed air.

[0111] The compressed air after cooling and still with residual moisture enters the collection area 49 on the input side of the air dryer 40 from the output end of the aftercooler 22 via the fourth compressed air line DL4. The condensed water also enters the collection area 49 of the air dryer 40 in the form of entrained droplets or as a water film. In the subsequent regeneration process, the water W is separated from the air dryer 40 via the regeneration air output end 42 of the air dryer 40. As a result, the condensed water does not enter the drying medium 41 of the air dryer 40. Figure 8 This is also schematically illustrated with small droplets. The compressed air from the short fourth compressed air line DL4, which is partially dehydrated in this way and still has residual moisture, enters the drying medium 41 of the air dryer 40, flows through the drying medium 41 in the drying air flow 23 and is dried there. The drying medium 41 can absorb the air humidity from the compressed air provided and release it again to the dry air during the subsequent regeneration process.

[0112] The dried compressed air then leaves the air dryer 40 via the first spring-loaded nonreturn valve 29 which is blocked in the direction of the air dryer 40 and then enters the fifth compressed air line DL5. The fifth compressed air line DL5 leads to the already described multi-circuit protection valve 50, which is at least indirectly controlled by the control and regulator 28. For this purpose, the multi-circuit protection valve 50 is connected to the control and regulator 28 via a sensor line 56. Via the multi-circuit protection valve 50, the dried compressed air can be guided, for example, via the already described sixth compressed air line DL6 and the compressed air outlet opening 10 in the housing 6 to the first compressed air consumer 51 and via the described seventh compressed air line DL7 to the second compressed air consumer 52. The multi-circuit protection valve 50 can guide the dried compressed air via the eighth compressed air line DL8 to at least one compressed air reservoir 45. As required, compressed air can also be supplied to other compressed air consumers and / or compressed air reservoirs (not shown) via the compressed air reservoir 45. As required, the compressed air stored in the compressed air storage 45 may also be delivered to other compressed air consumers via the multi-circuit protection valve 50 , or returned to the fifth compressed air line DL5 for regenerating the drying medium 41 of the air dryer 40 .

[0113] If a predetermined air pressure is set in the compressed air consumers 51, 52 and in at least one compressed air reservoir 45 and the electric motor 24 of the compressor module 90 is turned off, the drying medium 41 arranged in the air dryer 40 and saturated with water can be regenerated, that is, the water stored there can be removed. For this purpose, the compressed air production device 2.7 has a regeneration line DL5a. The regeneration line DL5a is indirectly connected to at least the eighth compressed air line DL8 leading to the compressed air reservoir 45 via the fifth compressed air line DL5, and is indirectly connected to the air dryer 40. The first two-position three-way electromagnetic switching valve 72 mentioned above is arranged in the regeneration line DL5a, which is connected to the control and regulator 28 via the control line 55 and can be driven by the control and regulator.

[0114] When the first two-position three-way electromagnetic switching valve 72 is not operated, the regeneration line DL5a is as follows: Figure 84 is shown as closed, so that no compressed air can enter the air dryer 40 from the compressed air reservoir via the multi-circuit protection valve 50. In order to perform the regeneration operation of the air dryer 40, the first two-position three-way solenoid switching valve 72 is operated, resulting in the regeneration line DL5a being in an open state. As a result, part of the compressed air in the dried compressed air enters the throttle 75 from the compressed air reservoir 45 through the first line branch DL5b of the regeneration line DL5a. There, the dried compressed air expands, thereby increasing the volume of the compressed air. Subsequently, the compressed air passes through the spring-loaded second check valve 76 opened in the direction of the air dryer 40, and then enters the air dryer 40 via the regeneration compressed air inlet 70. Then, as long as the pressure-controlled two-position two-way switching valve 39 at the collection area 49 of the air dryer 40, which acts as an exit valve, is in an open state, the expanded compressed air flows through the air dryer 40 and the drying medium 41 arranged there in the regeneration compressed air flow 77.

[0115] In order to operate the pressure-controlled 2 / 2-way switching valve 39, another part of the dried compressed air is guided to the pressure-controlled 2 / 2-way switching valve 39 through the second line branch DL5c after the output of the first 2 / 2-way solenoid switching valve 72. The pressure-controlled 2 / 2-way switching valve 39 is designed so that in the non-operated switching position it closes the connection from the collection area 49 of the air dryer 40 to the regeneration air output 42 of the air dryer 40, and in the operated switching state it opens the connection. Therefore, when the first 2 / 2-way solenoid switching valve 72 is switched to its open position, the pressure-controlled 2 / 2-way switching valve 39 will also be in the open state.

[0116] According to the alternative embodiment, there are two two-way solenoid switching valves that can be driven by the control and regulator 28 to replace the first two-way three-way solenoid switching valve 72. These two two-way solenoid switching valves are not shown in the figure, but their arrangement can be easily understood by those skilled in the art based on the following description. The first two-way solenoid switching valve is arranged in the first line branch DL5b before the throttle 75 along the flow direction of the regeneration compressed air, and the second two-way solenoid switching valve is arranged in the second line branch DL5c before the pressure-controlled two-way solenoid switching valve 39. In addition, here, the fifth compressed air line DL5 is directly connected to the first line branch DL5b and directly connected to the second line branch DL5c before the two two-way solenoid switching valves along the flow direction of the regeneration compressed air. Once the two two-way solenoid switching valves are switched to their open positions, the dry regeneration compressed air can be guided to the silencer 43 through the air dryer 40 when the pressure-controlled two-way switching valve 39 is also opened, so as to dry the drying medium 41.

[0117] In addition, with the help of this structure, when the first two-position two-way solenoid switching valve is closed, the second two-position two-way solenoid switching valve is opened, and thus the pressure-controlled two-position two-way switching valve 39 is opened, the water W accumulated there can be advantageously removed by means of compressed air supplied to the collection area 49 of the air dryer 40 via the aftercooler 22.

[0118] Now back again Figure 8 In the embodiment shown in FIG. 1 , when the two-position two-way switching valve 39 is opened under pressure control, the expanded compressed air in the regeneration compressed air flow 77 will flow through the drying medium 41 in the direction of the silencer 43. At this time, moisture is extracted from the drying medium 41. Subsequently, the compressed air enriched with moisture in this way and the moisture that has condensed and accumulated in the collection area 49 of the air dryer 40 will leave the air dryer 40 via the regeneration air outlet 42 of the air dryer and thus enter the silencer 43.

[0119] Then, the moist regeneration exhaust gas AL flows through the silencer material 44 arranged in the silencer 43 and flows to the at least one regeneration air outlet opening 34 of the silencer 43 of the compressed air generating device 2.7 via the exhaust gas path 78. Water droplets that may be formed in the regeneration compressed air flow or in the silencer material 44 of the silencer 43 when the regeneration compressed air flow passes through the silencer 43, as well as condensed water from the collecting area 49 of the air dryer 40, flow in the silencer 43 via the water separation path 80 described above toward the at least one water outlet opening 36 of the silencer. However, the at least one water outlet opening 36 of the silencer 43 is also used to remove splash water that may penetrate into the silencer 43 via the at least one regeneration air outlet opening 34 again.

[0120] The regeneration process ends when a predetermined, sufficiently large volume of regeneration compressed air has flowed through the drying medium 41 of the air dryer 40 so that it can be used for a further air drying phase.

[0121] The flow path of the liquid cooling medium delivered from the first external cooling device 82 is very important for the construction of the compressed air generating device 2.7 according to the present invention. The cooling medium is cooled to a predetermined temperature in the first external cooling device 82 and delivered to the compressed air generating device 2.7 via the cooling medium delivery line Kin. The cooling activity of the first external cooling device 82 is controlled and regulated by the control and regulator 28. In the case where the cooling medium temperature is preferably regulated, the current actual temperature of the cooling medium is measured by the first temperature sensor 73 at the output end of the first external cooling device 82, and then the cooling medium temperature is adjusted to a predetermined target value of the cooling medium temperature. To this end, the first temperature sensor 73 is connected to the control and regulator 28 via a data and / or sensor line 59.

[0122] From the first external cooling device 82, the cooling medium enters the compressed air generating device 2.7 through the cooling medium inlet opening 12 and enters the compressed air cooling module 92. Subsequently, the cooling medium flows into the aftercooler 22 via the first cooling medium line KL1 in order to cool the compressed air generated by the compressor 4 there as much as possible. Since the cooling medium is first guided into the aftercooler 22, the lowest temperature of the cooling medium within the compressed air generating device 2.7 can be utilized. As a result, the compressed air is already cooled to a relatively large extent before it is introduced into the air dryer 40, as a result of which part of the entrained air humidity is condensed and at least partially separated in the aftercooler 22. The condensed water is also guided into the collecting area 49 of the air dryer 40 and discharged from there directly or via the silencer 43 to the surrounding environment. Through this process, a large amount of water can be extracted from the compressed air before it reaches the air dryer 40. The lower the temperature of the cooling medium, the more water is extracted.

[0123] Therefore, compared to conventional compressed air generating devices, the drying medium 41 of the air dryer 40 will be dried less frequently during the regeneration process, or such a regeneration process can be performed with a smaller volume of regeneration compressed air than is usually the case. As a result, more of the dry compressed air stored in the compressed air reservoir 45 is provided to the compressed air consumers 51, 52, so that the electric motor 24 of the compressor 4 of the compressed air generating device 2.7 does not need to be put into operation so frequently. As a result, for example, when such a compressed air generating device 2.7 is arranged in a vehicle and operated, the consumption of electrical energy is reduced, thereby reducing the exhaust gas emissions of the vehicle and thus the CO2 emissions of the vehicle. 2 output.

[0124] Therefore, the lower the temperature of the cooling medium at the outlet of the aftercooler 22, the lower the frequency of the regeneration process or the respectively required volume of compressed air for regeneration can be. It is therefore advantageous that the control and regulator 28 also regulates the actuation frequency and / or the actuation duration of the regeneration switching valve designed as the first two-position three-way solenoid switching valve 72 in dependence on the temperature of the cooling medium. For this purpose, as already briefly mentioned above, according to Figure 8In the embodiment shown in , a first temperature sensor 73 is arranged in the area of ​​the output end of the external cooling device 82 or in the area of ​​the coolant inlet opening 12, by means of which the temperature of the liquid coolant can be measured. Usually, such a temperature sensor 73 is already a component of the first external cooling device 82, so that the use of the temperature sensor does not cause additional production costs. The temperature measurement value obtained in this way can be guided to the control and regulator 28 via the data and / or sensor line 59. Then, the control and regulator 28 controls and regulates the regeneration of the drying medium 41 of the air dryer 40 directly via the actuation frequency and / or actuation duration of the first two-position three-way electromagnetic switching valve 72 and indirectly by means of the pressure-controlled two-position two-way switching valve 39, taking into account the current coolant temperature.

[0125] Figure 8 Also shown are alternative solutions to this, according to which the temperature of the cooling medium can be measured at the cooling medium input of the aftercooler 22 by means of a second temperature sensor 73' and / or at the cooling medium output of the aftercooler 22 by means of a third temperature sensor 73". These temperature sensors 73', 73" are likewise connected to the control and regulator 28 via data and / or sensor lines 59. The data and / or sensor lines 59 connected to the respective temperature sensors 73, 73', 73" can also be connected to the control and regulator 28. Figure 8 The different methods are completely arranged within the compressed air generating device 2.7.

[0126] In such regulation, it should also be noted that during the operation of the compressed air generating device 2.7, the temperature of the cooling medium may fluctuate. This may be caused by different load states of the vehicle and its systems and / or by rapidly changing ambient temperatures. In most vehicles, since the current temperature of the cooling medium is measured by means of the first temperature sensor 73 for regulating the first external cooling device 82 mentioned, the respective current value of the temperature of the cooling medium is provided to the control and regulator 28 via the already mentioned data and / or sensor line 59 of the CAN bus. Based on the current value of the cooling medium temperature, the control and regulator 28 can control and regulate the actuation duration of the two-position three-way electromagnetic switching valve 72 and thus the frequency and duration of the regeneration process of the dryer 40 at any time in a temperature-dependent manner.

[0127] Since most vehicles in traffic today also use an ambient temperature sensor 74 to measure the vehicle's ambient temperature and display it using a display element, the ambient temperature is also provided to the control and regulator 28 via the data and / or sensor line 59 of the CAN bus for controlling and adjusting the actuation duration of the first two-position three-way solenoid switching valve 72, and further for controlling and adjusting the frequency and duration of the regeneration process on the air dryer 40.

[0128] The ambient temperature of the vehicle is very important for controlling and regulating the regeneration process, since the compressed air continues to cool down after it has been dried in the dryer 40 until it reaches the temperature of the compressed air tank 45 or the compressed air consumers 51, 52, which usually have the temperature of the ambient environment. During this further cooling process, the relative humidity in the compressed air rises again. In order not to cause corrosion processes or even condensation of water and ice formation when the ambient temperature in the compressed air reservoir and in the compressed air consumers is lower than the temperature of the coolant, the dryness of the compressed air must ideally also take into account the current ambient temperature.

[0129] This dryness can be adjusted via the volume of regeneration compressed air used during the regeneration process and / or the frequency of regeneration within the time period of interest. For example, if a substantially excessive volume of regeneration compressed air is used during the regeneration process, the drying medium 41 becomes drier than required by the previously known practice. As a result, during the subsequent transport process, the compressed air guided through the air dryer 40 will lose more moisture than previously required, so that the compressed air has a higher dryness when it leaves the air dryer 40. When the compressed air is further cooled in the compressed air container or the compressed air consumer, the dryness of the compressed air is advantageously very high, so that no condensation and possible ice formation occurs there during the further cooling of the compressed air.

[0130] Thus, the regeneration compressed air volume and / or the frequency of the regeneration process are controlled and regulated by means of the control and regulation device 28 when the ambient temperature remains constant as a function of the temperature of the cooling medium, and when the cooling medium temperature remains constant as a function of the ambient temperature. If both the ambient temperature and the cooling medium temperature change, the duration and / or the frequency of the regeneration process will be controlled and regulated as a function of the difference between the two mentioned temperatures.

[0131] If this regulation is omitted, the volume of regeneration compressed air required for each regeneration process must also cover the most unfavorable case, i.e., taking into account the maximum temperature of the cooling medium to be expected during operation of the compressed air generating device 2.7. As a result, such a regeneration process for the drying medium 41 is always carried out using the maximum regeneration compressed air volume known in advance.

[0132] Now, the further use of the liquid cooling medium is described: After flowing through the aftercooler 22, the liquid cooling medium enters the aforementioned intercooler 20 via the second cooling medium line KL2, where the compressed air pre-pressed by the first air compressor 16 is cooled. After cooling the pre-compressed compressed air in the intercooler 20, the liquid cooling medium is guided to the cooling device 25 of the electric motor 24 via the third cooling medium line KL3. There, the cooling medium cools the stator of the electric motor 24, for example.

[0133] Subsequently, the cooling medium flows via the fourth cooling medium line KL4 to the cooling device 48 of the second air compressor 18 of the compressor 4, thereby cooling the second air compressor during its compression activity. Then, the cooling medium flows via the fifth cooling medium line KL5 to the cooling device 27 of the inverter 26 in order to also cool the inverter. After that, the cooling medium flows via the sixth cooling medium line KL6 to the cooling device 46 of the first air compressor 16 of the compressor 4 in order to also cool the first air compressor. Finally, the heated cooling medium is guided from the compressor module 90 and the housing 6 of the compressed air generating device 2.7 via the cooling medium discharge line Kout to the first external cooling device 82 through the cooling medium delivery opening 14.

[0134] Studies have shown that a relatively large degree of cooling of the compressed air in the aftercooler 22 has no negative effect on the operation of the compressed air generating device 2.7. Even further advantages can be seen. This will be explained in conjunction with the following example:

[0135] In this case, the compressed air generating device 2.7 designed according to the invention is installed in a truck and uses a cooling system for cooling a liquid cooling medium, which also cools the internal combustion engine of the truck and serves as a heat source for heating the interior. When the internal combustion engine is cold started, i.e. when the internal combustion engine is started at very low ambient temperatures, if the temperature of the cooling system of the internal combustion engine quickly rises above the ambient temperature, this is advantageous in terms of the operating characteristics of the vehicle battery, in terms of reducing the exhaust gas emissions of the truck, and in terms of providing warm air for heating the interior of the truck. Since the electrically operated compressed air generating device 2.7 is also put into operation at the same time when the internal combustion engine is cold started to generate the compressed air required for operation, the compressed air is cooled as much as possible by the liquid cooling medium. As a result, the waste heat extracted from the compressed air generating device 2.7, in particular the heat generated by the operation of the electric motor 24, the inverter 26 and the two air compressors 16, 18, is advantageously used indirectly via the heated liquid cooling medium to also relieve the load on the vehicle battery. In this case, during the cold start of the truck and during the short warm-up phase, temperatures at which ice can form at the inlet of the aftercooler 22 and the air dryer 40 can also be tolerated. Since the warm-up phase is relatively short, any ice that may form at the inlet of the aftercooler 22 and the air dryer 40 will evaporate during the subsequent normal operating phase and be absorbed as air humidity in the compressed air.

[0136] Figures 1 to 7 The compressed air generating devices 2.3, 2.4, 2.5, 2.6, 2.8, 2.9 shown in FIG. 1 also have a large number of features in combination with the Figure 8 The compressed air generating device 2.7 has the design features explained and works according to the method. Therefore, according to the present invention, Figures 1 to 8 In all the compressed air generating devices 2.3, 2.4, 2.5, 2.6, 2.7, 2.8 and 2.9 shown in the drawing, it is provided that the air cooler 22 which is arranged as the last air cooler before the air dryer 40 in the compressed air flow direction can be first flowed through by the coolant as seen in the coolant flow direction.

[0137] Figures 1 to 8 All compressed air generating devices 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, and 2.9 shown in the drawings also have another advantageous feature, in that the control and regulator 28 is constructed and arranged so that the operation of the electric motor 24, the drying operation and regeneration operation of the air dryer 40, and the operation of the multi-circuit protection valve 50 can be controlled and regulated by means of the control and regulator.

[0138] At this point, reference Figures 4 to 8It should be pointed out that the silencer 43 or the silencer module 96 is connected or connectable to the housing 6 of the respective compressed air generating device 2 . 3 to 2 . 7 and the lines therein, but is not structurally integrated into the housing 6 .

[0139] exist Figure 4 The embodiment of the compressed air generating device 2.3 having the features of the invention shown in FIG. Figure 8 Like the first embodiment of the compressed air generating device 2.7, it has a separate compressed air cooling module 92, which is arranged between the compressor module 90 and the dryer module 94. Figure 1 , Figure 2 and Figure 8 The compressed air generating equipment 2.7, 2.8, 2.9 is different in that, according to Figures 4 to 7 The compressed air generating devices 2.3 to 2.6 of the embodiment of the present invention have an air inlet 8* for sucking in ambient air L, which is not configured on the compressor module 90, but on the silencer 43 or the silencer module 96. In order to save production costs, the air inlet 8* is identical to the at least one regeneration air outlet opening 34 that is only required for the compressed air generating device when the respective compressed air generating device is operated in the regeneration mode. At the rest of the time, that is, during most of the operating time, the at least one regeneration air outlet opening 34 serves as an air inlet 8*, through which ambient air L can be sucked toward the first air compressor 16.

[0140] In accordance with Figures 4 to 7 In these compressed air generating devices 2.3 to 2.6, ambient air L enters from the alternately usable openings 8*, 34 in the silencer 43 or the silencer module 96 via the silencer material 44 arranged there and the suction line DL to the input end of the first air compressor 16, so as to be compressed into compressed air in the first air compressor in a first compression process. Subsequently, the compressed air will follow the Figure 8 The flow path has already been explained in the description of the compressed air generating device 2.7.

[0141] Figure 5 The improved scheme of the compressed air generating device 2.4 shown in Figure 4The compressed air generating device 2.3 of the present invention is designed largely in the same manner. Since the suction and conduction of the ambient air L through the sound-absorbing material 44 of the silencer 43 can cause the sound-absorbing material to be subjected to an undesirably large degree of load from penetrating splash water, air humidity and dust particles, a water and particle separator 88 is arranged in or on the silencer 43 in the compressed air generating device 2.4. The water W filtered out of the sucked-in ambient air L by the water and particle separator 88 is conducted together with the filtered-out dirt particles to the water discharge opening 36 of the silencer 43, where it is discharged into the surrounding environment.

[0142] Figure 6 Another variant of a compressed air generating device 2.5 having the features of the present invention is shown in FIG. Figure 4 The difference between the compressed air generating device 2.3 shown in FIG. 2 is that the multi-circuit protection valve 50 does not belong to the dryer module 94. Figure 6 As shown, the multi-circuit protection valve 50 can be arranged away from the dryer module 94 or arranged and operated away from the compressed air generating device 2.5. For this purpose, the multi-circuit protection valve 50 has a pneumatic connection mechanism 62 on the input side, via which the multi-circuit protection valve 50 is connected to the fifth compressed air line DL5 of the dryer module 94 further described above in a detachable manner. In addition, the multi-circuit protection valve 50 has a pneumatic connection mechanism 66 on the output side, via which the multi-circuit protection valve 50 is connected to the sixth, seventh and eighth compressed air lines DL6, DL7, DL8 in a detachable manner. As mentioned above, these compressed air lines DL6, DL7, DL8 lead to compressed air consumers 51, 52 and at least one compressed air reservoir 45. In addition, the multi-circuit protection valve 50 also has an electrical connection mechanism 64, by means of which the multi-circuit protection valve 50 is connected to the electrical connection mechanism 68 of the control and regulator 28 in a detachable manner.

[0143] The pneumatic connection mechanisms 62, 66 are preferably configured as compressed air connection sockets, into which compressed air plugs can be inserted in a detachable manner. These compressed air plugs are arranged at the end sides of the compressed air lines DL5, DL6, DL7 and DL8. These compressed air lines DL5, DL6, DL7, DL8 can be configured as flexible compressed air lines.

[0144] The electrical connection mechanism 64 on the multi-circuit protection valve 50 is preferably configured as an electrical socket. The electrical plug of the sensor line 56 is inserted into the electrical socket in a detachable manner, and the other end of the sensor line has a second electrical plug, which can also be inserted into the associated electrical connection mechanism 68 configured as a socket on the control and regulator 28 in a detachable manner.

[0145] Due to the described structure of the compressed air generating device 2.5, the multi-circuit protection valve 50 can also be arranged away from the compressed air generating device 2.5, so that when the compressed air generating device 2.5 is damaged, the multi-circuit protection valve does not have to be removed from the compressed air system of the vehicle for maintenance purposes.

[0146] It should be noted here that the control and regulator 28 is designed and connected to other components of the compressed air generating device 2.5 via sensor lines and control lines in such a way that the control and regulator 28 can control and regulate the operation of the inverter 26 and thus the operation of the electric motor 24 as well as the drying operation and regeneration operation of the air dryer 40. In addition, the control and regulator 28 can also at least indirectly control and regulate the operation of the multi-circuit protection valve 50.

[0147] The control and regulating device 28 can be structurally integrated, for example, in the inverter 26 or the multi-circuit protection valve 50. This prevents the control and regulating device 28 from being left on the vehicle in the case of maintenance.

[0148] also, Figure 7 2.3 shows another embodiment of a compressed air generating device 2.6 having the features of the present invention. Figure 5 In the embodiment shown in , it is also provided that the multi-circuit protection valve 50 can be separated from other components of the compressed air generating device 2.6 and can be operated away from these components. For this purpose, the control and regulator 28 and the multi-circuit protection valve 50 have electrical connections 64, 68, which are at least indirectly connected to each other in a detachable manner by means of at least one flexible electrical line 56, 102. In addition, the multi-circuit protection valve 50 has a pneumatic connection 62, which is at least indirectly connected to the output of the air dryer 40 via at least one flexible pneumatic line 106 in a detachable manner.

[0149] The compressed air generating device 2.6 therefore has an electric motor 24 and two air compressors 16, 18 which can be driven by the electric motor 24 and act in sequence. The compressed air generating device 2.6 also has an air inlet 8*, via which ambient air L can be sucked in by means of the first air compressor 16. In addition, there is an intercooler 20 and an aftercooler 22, wherein the input of the intercooler 20 is pneumatically connected to the output of the first air compressor 16, wherein the output of the intercooler 20 is pneumatically connected to the input of the second air compressor 18, and wherein the output of the second air compressor 18 is pneumatically connected to the input of the aftercooler 22. In addition, there is an air dryer 40, the input of which is pneumatically connected to the output of the aftercooler 22. There is a cooling medium inlet opening 12 for supplying cooling medium, via which liquid cooling medium can be supplied from the first external cooling device 82 to the intercooler 20 and the aftercooler 22. The heated coolant can be discharged toward the first external cooling device 82 via the coolant discharge opening 14 and the coolant discharge line Kout.

[0150] according to Figure 7 The compressed air generating device 2.6 feeds compressed air to the multi-circuit protection valve 50, via which the output of the air dryer 40 is pneumatically connected to at least one external compressed air reservoir 45 and external compressed air consumers 51, 52. In addition, there is a control and regulator 28, which is connected to the multi-circuit protection valve 50 and the sensor arranged there via at least one sensor line 56.

[0151] In accordance with Figure 7 In the compressed air generating device 2.6, it is provided that the dryer module 94* having the air dryer 40 has at least one electrical socket 100 and at least one pneumatic socket 104. The electrical socket 100 of the dryer module 94* is connected to the electrical socket 68 on the control and regulator 28 via the sensor line 56 on the output side. The electrical plug of the electrical connection line 102 is detachably inserted into the electrical socket 100 of the dryer module 94 on the input side. The electrical connection line 102 has a second plug that is detachably inserted into the electrical socket 64 of the multi-circuit protection valve 50.

[0152] The pneumatic socket 104 of the dryer module 94* is pneumatically connected to a fifth compressed air line DL5, through which the dried compressed air from the air dryer 40 can be conducted to the compressed air consumers 51, 52 and the compressed air reservoir 45. The plug of the pneumatic connecting line 106 is detachably inserted into the pneumatic socket 104 of the dryer module 94*. The pneumatic connecting line 106 has a second plug detachably inserted into the pneumatic socket 62 of the multi-circuit protection valve 50.

[0153] In accordance with Figure 7 In a compressed air generating device 2.6, the multi-circuit protection valve 50 is arranged relatively far from the remaining components of the compressed air generating device 2.6. The achievable distance is determined in particular by the maximum reasonable length of the electrical connection line 102 and the pneumatic connection line 106. For example, such a compressed air generating device 2.6 is used in a vehicle combination consisting of a tractor vehicle and a plurality of trailer vehicles, wherein the multi-circuit protection valve 50 is arranged on one of the trailer vehicles, but the core components of the compressed air generating device 2.6 are arranged on the tractor vehicle.

[0154] In particular, it can be achieved that the compressed air lines DL6, DL7, DL8, which start from the multi-circuit protection valve and lead to the compressed air consumers 51, 52 and the at least one compressed air reservoir 45, can be kept relatively short. The production costs can thus be reduced, and the risk of line damage can be reduced due to the reduced overall length. In addition, the air dryer module 94* can be designed to be narrower, which can be advantageous if the installation space conditions on the vehicle are limited.

[0155] like Figure 7 As indicated in , according to an alternative embodiment, the multi-circuit protection valve 50 and all the sensors and electromagnetic switching valves arranged therein can be connected to the central controller 110 of the vehicle via a single electrical line 108. In this variant, the central controller 110 is also electrically connected to the first 3 / 2-way electromagnetic switching valve 72 or to the two 2 / 2-way electromagnetic switching valves used therefor via at least one control line 112. Thus, the central controller 110 of the vehicle will also take over all other tasks of the control and regulator 28.

[0156] Figure 1 The variant of the compressed air generating device 2.8 with the features of the invention shown in the drawing does not show all the details of the air dryer 40 and the control devices arranged there for implementing the drying operation and regeneration operation, because these details are not important for the description of this device variant and only affect the clarity of the illustration.

[0157] Therefore, the compressed air generating device 2.8 comprises: a control and regulator 28; an electric motor 24; two air compressors 16, 18 which can be driven by the electric motor 24 and act in sequence; an air inlet end 8, through which ambient air L can be sucked in by means of the first air compressor 16; a first air cooler constructed and arranged as an intercooler 20 and a second air cooler constructed and arranged as an aftercooler 22, wherein the input end of the intercooler 20 is pneumatically connected to the output end of the first air compressor 16, wherein the output end of the intercooler 20 is pneumatically connected to the output end of the first air compressor 16 The air compressor 2.8 is pneumatically connected to the input end of the second air compressor 18, and the output end of the second air compressor 18 is pneumatically connected to the input end of the aftercooler 22; and an air dryer 40, the input end of the air dryer is pneumatically connected to the output end of the aftercooler 22; and a cooling medium inlet opening 12, through which the liquid cooling medium can be delivered to the intercooler 20 and the aftercooler 22 and other components of the compressed air generating device; and a cooling medium outlet opening 14, through which the heated cooling medium can be discharged. And, according to the present invention, it is also provided in the compressed air generating device 2.8 that the aftercooler 22, which is arranged as the last air cooler before the air dryer 40 in the compressed air flow direction, can be first flowed by the cooling medium from the cooling medium flow direction.

[0158] In accordance with Figure 1In the compressed air generating device 2.8, it is now provided as an improved solution of the subject of the present invention that the cooling medium input end of the aftercooler 22 is connected to the cooling medium inlet opening 12 via the first cooling medium line KL1, the cooling medium output end of the aftercooler 22 is connected to the cooling medium input end of the intercooler 20 via the second cooling medium line KL2, the cooling medium output end of the intercooler 20 is connected to the cooling medium input end of the dryer module cooler 40.1 via the seventh cooling medium line KL7, and the cooling medium output end of the dryer module cooler 40.1 is connected to the electric motor via the eighth cooling medium line KL8. 24, the cooling medium output of the electric motor 24 is connected to the cooling medium input of the second air compressor 18 via a fourth cooling medium line KL4, the cooling medium output of the second air compressor 18 is connected to the cooling medium input of the inverter 26 via a fifth cooling medium line KL5, the cooling medium output of the inverter 26 is connected to the cooling medium input of the first air compressor 16 via a sixth cooling medium line KL6, and the cooling medium output of the first air compressor 16 is connected to the cooling medium outlet opening 14 of the compressed air generating device 2.8 via a cooling medium outlet line Kout. The cooling medium inlet opening 12 and the cooling medium outlet opening 14 are hydraulically connected to the first external cooling device 82 mentioned above. In addition, a first temperature sensor 73 is arranged at the output of the first external cooling device 82, which is connected to the control and regulator 28 via a data line and / or a sensor line 59, and by means of which the cooling medium temperature at the output of the first external cooling device 82 can be measured.

[0159] It is particularly advantageous in this embodiment of the compressed air generating device 2.8 that the air dryer 40 or its components can also be actively cooled by means of a liquid cooling medium by means of the dryer module cooler 40.1. Thus, for example, the housing of the air dryer 40 can be cooled, so that the compressed air reaching the air dryer 40 has already been freed of air humidity by condensation before it flows through the drying medium 41. The condensed water W then preferably reaches a collecting area 49 (e.g. Figures 4 to 8 and are eventually discharged into the external environment.

[0160] Figure 2 and Figure 3 Schematically shown in FIG. 2 is a variant of a compressed air generating device 2 . 9 having features of the invention, which variant is described last here. Figure 3The simplified enlarged detail of the compressed air generating device 2.9 shows three external cooling devices 82, 120, 122, the intercooler 20, the aftercooler 22 and the respectively associated lines for conducting liquid cooling medium and compressed air. The three cooling devices 82, 120, 122 can be used alternately or superimposedly to cool the compressed air and components of the compressed air generating device 2.9 as required.

[0161] The compressed air generating device 2.9 has the components already mentioned several times, and it is not necessary to describe them again here. However, it is important in the compressed air generating device 2.9 that three external cooling devices 82, 120, 122 can be connected to it, which are used as required under the control of the control and regulator 28.

[0162] Therefore, according to Figure 2 and Figure 3 In a first operating mode, the compressed air generating device 2 . 9 can cool its components and the compressed air only by means of the first external cooling device 82 , ie when the temperature of the liquid cooling medium is lower than the temperature of the compressed air generated by the two air compressors 16 , 18 .

[0163] To this end, it is provided that the coolant inlet opening 12 is hydraulically connected to the first external cooling device 82, and a first cooling switching valve 130 is arranged in the first coolant line KL1 extending from the coolant inlet opening 12 to the coolant input end of the aftercooler 22. The first cooling switching valve 130 is constructed as a two-position two-way electromagnetic switching valve, which is connected to the control and regulator 28 via control technology, and with the help of the first cooling switching valve 130, depending on its switching position, the first coolant line KL1 can be cut off, or as mentioned above, it can be opened when the coolant temperature is low.

[0164] However, it is also possible that if the temperature of the liquid coolant is higher than the temperature of the compressed air, the coolant is not used to cool the compressed air in the aftercooler 22 and the intercooler 20, but is used to cool the electric motor 24, the inverter 26 and the two air compressors 16, 18.

[0165] In this respect, the control mode for utilizing the cooling medium of the first external cooling device is carried out by means of the control and regulator 28, which uses the measured value of the first temperature sensor 73 and can drive the electromagnetic switching valve (not shown in the figure) assigned, not shown in the figure and arranged in a special cooling medium line, for bypassing the aftercooler 22 and the intercooler 20. The special cooling medium line connects the cooling medium inlet opening 12 to the input end of the cooling device 25 of the electric motor 24. The special electromagnetic switching valve is configured as a two-position two-way electromagnetic switching valve, for example. When the cooling medium temperature of the first external cooling device 82 is higher than the temperature of the compressed air in the aftercooler 22, but lower than the temperature of the cooling device 25 of the electric motor 24, the cooling device 27 of the inverter 26 and / or the first air compressor 48 and / or the cooling device 46, 48 of the second air compressor 18, the two-position two-way electromagnetic switching valve is opened when the first cooling switching valve 130 is closed. This ensures that cooling medium is supplied from the first external cooling device 82 to the electric motor 24 , the inverter 26 and the two air compressors 16 , 18 for cooling them, even if the temperature of the cooling medium is higher than the temperature of the compressed air in the aftercooler 22 .

[0166] If the temperature of the cooling medium at the output end of the first external cooling device 82 and / or at the input end of the aftercooler 22 is too high to cool the compressed air in the aftercooler 22, it is provided that the output end of the first air compressor 16 can be connected to the input end of the second external cooling device 120 via the second cooling switching valve 132 configured as a two-position three-way electromagnetic switching valve, the second cooling switching valve 132 is connected to the control and regulator 28 through control technology, and the output end of the second external cooling device 120 is pneumatically connected to the input end of the second air compressor 18. Then, the compressed air enters the aftercooler 22 from the output end of the second air compressor 18, and from there enters the air dryer 40. Since the aftercooler 22 is passive with respect to the cooling of the compressed air in this operating condition, the flow through the aftercooler does not have a heating effect on the compressed air.

[0167] If the cooling power of the second external cooling device 120 is insufficient to cool the compressed air to the desired degree, the third external cooling device can be connected as an auxiliary. Therefore, another design scheme provides that the output end of the second air compressor 18 can be connected to the input end of the third external cooling device 122 via the third cooling switching valve 134 configured as a two-position three-way electromagnetic switching valve, the third cooling switching valve 134 is connected to the control and regulator 28 through control technology, and the output end of the third external cooling device 122 is connected to the input end of the air dryer 40.

[0168] It can be seen that when the second external cooling device 120 and the third external cooling device 122 are used, the temperature of the compressed air can be adjusted to a desired value, thereby enabling the air humidity in the compressed air to be condensed to a large extent before reaching the air dryer 40 or its drying material 41. The second external cooling device 120 and the third external cooling device 122 can be configured as air-to-air heat exchangers. Figure 3 As shown in the region marked therein, A, the compressed air in the lines leading to the two external cooling devices 120 , 122 is conducted in opposite directions to one another.

[0169] For use according to Figure 1 The method of the compressed air generating device 2.8 is arranged such that the coolant from the cooling medium output end of the intercooler 20 is not directly transported to the cooling medium input end of the electric motor 24, but is transported to the cooling medium input end of the electric motor 24 via the dryer module cooler 40.1, and the dryer module cooler 40.1 at least cools the components of the air dryer 40, such as its housing.

[0170] To use according to Figure 2 and Figure 3 The method of the compressed air generating device 2.9 is arranged that the temperature of the cooling medium is measured at the output end of the first external cooling device 82 or at the input end of the aftercooler 22, and when the obtained temperature of the cooling medium reaches or exceeds a first high limit value specified in advance, the compressed air from the output end of the first air compressor 16 is no longer transported via the intercooler 20, but via the second external cooling device 120 to the input end of the second air compressor 18.

[0171] In addition, according to the method, it can be set that the temperature of the cooling medium is measured at the output end of the first external cooling device 82 or at the input end of the aftercooler 22, and when the temperature of the cooling medium reaches or exceeds a second boundary value that is predetermined and is greater than the first boundary value, the compressed air from the output end of the first air compressor 16 is not transported via the intercooler 20, but is transported to the input end of the second air compressor 18 via the second external cooling device 120, and then additionally, the compressed air from the output end of the second air compressor 18 is not transported via the aftercooler 22, but is guided to the output end of the aftercooler 22 or the input end of the air dryer 40 via the third external cooling device 122.

[0172] The first external cooling device 82 is therefore not used to cool the compressed air, but the two other external cooling devices 120 , 122 are used for this purpose. In addition to bypassing the intercooler 20 , the compressed air also bypasses the aftercooler 22 .

[0173] Finally, as previously mentioned, according to the method it is provided that the liquid cooling medium of the first external cooling device 82 is guided through the cooling devices 25 , 27 , 46 , 48 of the electric motor 24 , of the inverter 26 and of the two air compressors 16 , 18 , even when no compressed air is guided through the intercooler 20 and / or the aftercooler 22 .

[0174] List of reference numerals (part of the description)

[0175] 2.3 Compressed Air Generating Equipment (First Embodiment)

[0176] 2.4 Compressed Air Generating Equipment (Second Embodiment)

[0177] 2.5 Compressed Air Generating Equipment (Third Embodiment)

[0178] 2.6 Compressed Air Generating Equipment (Fourth Embodiment)

[0179] 2.7 Compressed Air Generating Equipment (Fifth Embodiment)

[0180] 2.8 Compressed Air Generating Equipment (Sixth Embodiment)

[0181] 2.9 Compressed Air Generating Equipment (Seventh Embodiment)

[0182] 4 Compressor

[0183] 6 Housing of compressed air generating equipment

[0184] 8 Air Inlet Port (First Embodiment)

[0185] 8* Air inlet (second embodiment), opening in the muffler

[0186] 10 Compressed air outlet opening

[0187] 12 Cooling medium inlet opening

[0188] 14 Cooling medium outlet opening

[0189] 16 First Air Compressor

[0190] 18 Second air compressor

[0191] 20 Intercooler, air cooler

[0192] 22 Aftercooler, air cooler

[0193] 23 Dry air flow in air dryer

[0194] 24 Electric Motor

[0195] 25 Cooling equipment for electric motors

[0196] 26 Inverter

[0197] 27 Cooling equipment for inverter

[0198] 28 Control and Regulator

[0199] 29 First check valve

[0200] 30 First drive shaft

[0201] 32 Second drive shaft

[0202] 34 Regeneration air outlet opening, opening in silencer

[0203] 36 Water outlet opening of the silencer

[0204] 39 Pressure-controlled 2 / 2-way switching valve, outlet valve on air dryer

[0205] 40 Air Dryer

[0206] 40.1 Dryer Module Cooler

[0207] 41 Drying media in air dryers

[0208] 42 Regeneration air outlet of air dryer

[0209] 43 Silencer

[0210] 44 Sound-absorbing materials

[0211] 45 Compressed air storage tank

[0212] 46 Cooling equipment for the first air compressor

[0213] 48 Cooling equipment for the second air compressor

[0214] 49 Collection area for water in air dryer

[0215] 50 Multi-circuit protection valve

[0216] 51 First compressed air consumer

[0217] 52 Second compressed air consumer

[0218] 54 Control Line

[0219] 55 Control line from control and regulator to 3 / 2-way switching valve 72

[0220] 56 Sensor lines from control and regulator to multi-circuit protection valve

[0221] 57 Low voltage line

[0222] 58 High voltage line

[0223] 59 Data lines and / or sensor lines, CAN bus

[0224] 62 Pneumatic connection mechanism on the input side of the multi-circuit protection valve

[0225] 64 Electrical connection mechanism on multi-circuit protection valve

[0226] 66 Pneumatic connection mechanism on the output side of the multi-circuit protection valve

[0227] 68 Electrical connections on controls and regulators

[0228] 70 Regeneration compressed air input for air dryer

[0229] 72 Regeneration switching valve, first two-position three-way solenoid switching valve

[0230] 73 First temperature sensor (measures cooling medium temperature)

[0231] 73' Second temperature sensor (measures cooling medium temperature)

[0232] 73'' Third temperature sensor (measures cooling medium temperature)

[0233] 74 Fourth temperature sensor (measures ambient temperature)

[0234] 75 Throttle

[0235] 76 Second check valve

[0236] 77 Regeneration Compressed Air Flow in Air Dryer

[0237] 78 Exhaust gas path in the silencer

[0238] 80 Water separation path in silencer

[0239] 82 External cooling equipment

[0240] 88 Separators, water and particle separators

[0241] 90 Compressor Module

[0242] 92 Compressed air cooling module

[0243] 94 Dryer Module

[0244] 96 Silencer Module

[0245] 100 Electrical socket on dryer module

[0246] 102 Electrical connection lines

[0247] 104 Pneumatic socket on dryer module

[0248] 106 Pneumatic connection lines

[0249] 108 Electrical line from multi-circuit protection valve to controller 110

[0250] 110 Vehicle Central Controller

[0251] 112 Control line from controller 110 to solenoid switch valve 72

[0252] 120 Second external cooling device

[0253] 122 Third external cooling device

[0254] 130 First cooling switching valve, two-position two-way solenoid switching valve

[0255] 132 Second cooling switching valve, second two-position three-way solenoid switching valve

[0256] 134 Third cooling switching valve, third two-position three-way solenoid switching valve

[0257] 136 Control line from control and regulator to cooling switch valve

[0258] A Marking area

[0259] AL regeneration exhaust gas

[0260] DL Suction line for ambient air

[0261] DL1 First compressed air line

[0262] DL2 Second compressed air line

[0263] DL3 Third compressed air line

[0264] DL4 Fourth compressed air line

[0265] DL5 Fifth compressed air line

[0266] DL5a Regeneration Line

[0267] DL5b First line branch

[0268] DL5c Second line branch

[0269] DL6 Sixth compressed air line

[0270] DL7 Seventh compressed air line

[0271] DL8 Eighth Compressed Air Line

[0272] DL1.1 Ninth compressed air line

[0273] DL2.1 10th compressed air line

[0274] DL3.1 Eleventh compressed air line

[0275] DL4.1 12th compressed air line

[0276] KL1 First cooling medium line

[0277] KL2 Second cooling medium line

[0278] KL3 Third cooling medium line

[0279] KL4 Fourth cooling medium line

[0280] KL5 Fifth cooling medium line

[0281] KL6 Sixth cooling medium line

[0282] KL7 seventh cooling medium line

[0283] KL8 Eighth cooling medium circuit

[0284] Kin cooling medium delivery line

[0285] Kout Cooling medium discharge line

[0286] L Ambient air

[0287] W Water

Claims

1. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: a control and regulator (28); at least one controllable and adjustable electric motor (24); at least one air compressor (16, 18) that can be driven by the electric motor (24); an air inlet (8, 8*), through which ambient air (L) can be sucked into the at least one air compressor (16, 18); at least one air cooler (20, 22), the air cooler being connected to the at least one air compressor The compressed air generating device is characterized in that: the compressed air generating device is connected or can be connected to the output end of the compressor (16, 18); an air dryer (40), the input end of the air dryer is connected to the output end of the at least one air cooler (20, 22); a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the at least one air cooler (20, 22) and other components of the compressed air generating device; and a cooling medium outlet opening (14), through which the heated cooling medium can be discharged from the compressed air generating device, characterized in that The air cooler (22) which is arranged as the last air cooler before the air dryer (40) in the flow direction of the compressed air can be first flowed through by the cooling medium when viewed in the flow direction of the cooling medium.

2. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: a control and regulator (28); an electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*), through which ambient air (L) can be sucked in by means of a first air compressor (16); a first air cooler constructed and arranged as an intercooler (20) and a second air cooler constructed and arranged as an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected or connectable to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected or connectable to the input end of the aftercooler (22); an air dryer (40), the input end of the air dryer is pneumatically connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22) and other components of the compressed air generating device; and a cooling medium outlet opening (14), through which heated cooling medium can be discharged, characterized in that the aftercooler (22) arranged as the last air cooler before the air dryer (40) in the compressed air flow direction can be first flowed through by the cooling medium when viewed in the cooling medium flow direction.

3. The compressed air generating device (2.8) according to claim 2, characterized in that: The cooling medium input end of the aftercooler (22) is connected to the cooling medium inlet opening (12), the cooling medium output end of the aftercooler (22) is connected to the cooling medium input end of the intermediate cooler (20), the cooling medium output end of the intermediate cooler (20) is connected to the cooling medium input end of the dryer module cooler (40.1), the cooling medium output end of the dryer module cooler (40.1) is connected to the cooling medium input end of the electric motor (24), and the cooling medium output end of the electric motor (24) is connected to the cooling medium input end of the intermediate cooler (20). The cooling medium output end is connected to the cooling medium input end of the second air compressor (18), the cooling medium output end of the second air compressor (18) is connected to the cooling medium input end of the inverter (26) used to control and adjust the electric motor (24) with the help of the control and regulator (28), the cooling medium output end of the inverter (26) is connected to the cooling medium input end of the first air compressor (16), and the cooling medium output end of the first air compressor (16) is connected to the cooling medium delivery opening (14).

4. The compressed air generating device (2.8) according to claim 3, characterized in that The dryer module cooler (40.1) is designed and arranged in such a way that at least components of the air dryer (40) can be cooled by means of the dryer module cooler.

5. The compressed air generating device (2.9) according to claim 1 or 2, characterized in that: The cooling medium inlet opening (12) is hydraulically connected to a first external cooling device (82), and a first cooling switching valve (130) is arranged in a first cooling medium line (KL1) extending from the cooling medium inlet opening (12) to a cooling medium input end of the aftercooler (22). The first cooling switching valve (130) is constructed as a two-position two-way electromagnetic switching valve, which is connected to the control and regulator (28) via control technology, and with the help of the first cooling switching valve (130), the first cooling medium line (KL1) can be cut off or opened depending on its switching position.

6. The compressed air generating device (2.9) according to any one of claims 1 to 5, characterized in that The output end of the first air compressor (16) can be connected to the input end of the second external cooling device (120) via a second cooling switching valve (132) constructed as a two-position three-way electromagnetic switching valve, the second cooling switching valve (132) is connected to the control and regulator (28) through control technology, and the output end of the second external cooling device (120) is connected to the input end of the second air compressor (18).

7. The compressed air generating device (2.9) according to any one of claims 1 to 6, characterized in that The output end of the second air compressor (18) can be connected to the input end of the third external cooling device (122) via a third cooling switching valve (134) constructed as a two-position three-way electromagnetic switching valve, the third cooling switching valve (134) is connected to the control and regulator (28) through control technology, and the output end of the third external cooling device (122) is connected to the input end of the air dryer (40).

8. A compressed air generating device (2.9), comprising: a control and regulator (28); an electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8), through which the first air compressor (16) can draw in ambient air (L); a first air cooler constructed and arranged as an intercooler (20) and a second air cooler constructed and arranged as an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); an air dryer (40), wherein the input end of the air dryer is pneumatically connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which the cooling medium can be supplied to the intercooler (20) and the aftercooler (22) and the compressed air Another component of the air generating device is used to transport liquid cooling medium; and a cooling medium delivery opening (14) through which the heated cooling medium can be discharged, characterized in that the aftercooler (22) arranged as the last air cooler before the air dryer (40) along the compressed air flow direction can be first flowed by the cooling medium from the cooling medium flow direction, the cooling medium inlet opening (12) can be connected to the cooling medium output end of the first external cooling device (82), and the output end of the first air compressor (16) can be connected to the input end of the intercooler (20) via the first compressed air line (DL1). The first compressed air line (DL1) is pneumatically connected to the first compressed air line (DL1), a ninth compressed air line (DL1.1) is connected to the first compressed air line (DL1), and the ninth compressed air line can be pneumatically connected to the input end of the second external cooling device (120), the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18) via the second compressed air line (DL2), a tenth compressed air line (DL2.1) is connected to the second compressed air line (DL2), and the tenth compressed air line is pneumatically connected to the output end of the second external cooling device (120), the input end of the aftercooler (22) can be connected to the third compressed air line (DL2). The compressed air line (DL3) is pneumatically connected to the output end of the second air compressor (18), the third compressed air line (DL3) can be connected to the eleventh compressed air line (DL3.1), the eleventh compressed air line (DL3.1) is pneumatically connected to the input end of the third external cooling device (122), the output end of the third external cooling device (122) is connected to the fourth compressed air line (DL4) via a twelfth compressed air line (DL4.1), and the fourth compressed air line (DL4) connects the output end of the aftercooler (22) to the input end of the air dryer (40).

9. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8), comprising: a control and regulator (28); an electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*), through which ambient air (L) can be sucked in by means of a first air compressor (16); a first air cooler constructed and arranged as an intercooler (20) and a second air cooler constructed and arranged as an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); an air dryer (40), the input end of the air dryer is pneumatically connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which the cooling medium inlet opening can be supplied to the intercooler (20) and the aftercooler (22) and other parts of the compressed air generating device. The invention relates to a cooling medium conveying device for conveying liquid cooling medium; and a cooling medium discharge opening (14) through which the heated cooling medium can be discharged, characterized in that there is at least one temperature sensor (73, 73', 73"), which is arranged before the cooling medium input end and / or after the cooling medium output end of the air cooler (22) which is the last air cooler before the air dryer (40) in the flow direction of the compressed air for measuring the cooling medium temperature, and the at least one temperature sensor (73, 73', 73") is connected to the control and regulator (28) via a data or sensor line (59).

10. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8), comprising: a control and regulator (28); an electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*), through which ambient air (L) can be sucked in by means of a first air compressor (16); a first air cooler constructed and arranged as an intercooler (20) and a second air cooler constructed and arranged as an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); an air dryer (40), the input end of the air dryer is pneumatically connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22) and other components of the compressed air generating device; and a cooling medium delivery opening (14), through which the heated cooling medium can be discharged, characterized in that along the compressed The aftercooler (22) is arranged as the last air cooler before the air dryer (40) in the air flow direction and can be first flowed by the coolant from the coolant flow direction. There is at least one temperature sensor (73, 73', 73"), which is connected to the control and regulator (28) via a data or sensor line (59). In order to measure the coolant temperature, the temperature sensor (73, 73', 73") is arranged before the coolant input end or after the coolant output end of the aftercooler (22). The control and regulator (28) is constructed so that in addition to the operation of the electric motor (24), the drying operation and regeneration operation of the air dryer (40) and the operation of the multi-circuit protection valve (50) can also be controlled and regulated by the control and regulator.

11. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.9) according to any of the preceding claims, characterized in that In order to measure the cooling medium temperature, a temperature sensor (73) is arranged upstream of the cooling medium inlet opening (12) of the compressed air generating device.

12. The compressed air generating device (2.4, 2.7) according to any one of claims 9 or 10, characterized in that: In order to measure the coolant temperature, the temperature sensor (73') is arranged immediately before the coolant inlet of the aftercooler (22) which is arranged as the last air cooler before the air dryer (40) in the compressed air flow direction.

13. The compressed air generating device (2.4, 2.7) according to any one of claims 9 or 10, characterized in that: To measure the cooling medium temperature, the temperature sensor (73") is arranged as the next component after the cooling medium output of the aftercooler (22) which is arranged as the last air cooler before the air dryer (40) in the compressed air flow direction.

14. The compressed air generating device (2.4, 2.7) according to any one of claims 9 or 10, characterized in that: A temperature sensor (73', 73'') which is connected to the control and regulator (28) via signal technology is arranged at the coolant input and the coolant output of the aftercooler (22).

15. The compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) according to any one of claims 1 to 14, characterized in that The at least one electric motor (24), the inverter (26), the two air compressors (16, 18), the intercooler (20), the aftercooler (22), the air dryer (40), a multi-circuit protection valve (50) pneumatically connecting the output of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52), and a silencer (43) are arranged to cooperate with each other but are separated from each other.

16. The compressed air generating device (2.8, 2.9) according to any one of claims 1 to 14, characterized in that: The at least one electric motor (24), the inverter (26), the two air compressors (16, 18), the intercooler (20), the aftercooler (22), the air dryer (40), a multi-circuit protection valve (50) pneumatically connecting the output of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52), and a silencer (43) are arranged in or on a common housing (6).

17. The compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) according to any one of claims 1 to 16, characterized in that The control and regulator (28, 110) is arranged separately or in or on the housing (6); the control and regulator (28) is connected to the inverter (26) via a first control line (54) for controlling and regulating the electric motor (24); the control and regulator (28) is connected to a two-position three-way solenoid switching valve (72) via a second control line (55); the two-position three-way solenoid switching valve is used to open or close a regeneration line (DL5a) that pneumatically connects the compressed air reservoir (45) and the air dryer (40) at least indirectly; and the control and regulator (28) is connected to the multi-circuit protection valve (50) via a sensor line (56).

18. The compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) according to any one of claims 1 to 17, characterized in that A compressor module (90), a compressed air cooling module (92), a dryer module (94) and a silencer module (96) are arranged in or on the housing (6), together with the associated pneumatic, hydraulic and electrical lines, wherein the compressor module (90) has the electric motor (24), the inverter (26), the two air compressors (16, 18) and the control and regulator (28), wherein the compressed air cooling module (92) has the intercooler (20) and the aftercooler (22), wherein the dryer module (94) has the air dryer (40) and the multi-circuit protection valve (50), wherein the silencer module (96) has a silencer (43) with a sound-absorbing material (44), and wherein the silencer module (96) has at least one regeneration air outlet opening (34) for discharging regeneration compressed air into the surrounding environment.

19. A compressed air generating device (2.3, 2.4, 2.5, 2.6), comprising: at least one electric motor (24); at least one air compressor (16, 18) that can be driven by the electric motor (24); an air inlet (8*), through which ambient air (L) can be sucked in with the aid of the air compressor (16, 18); at least one air cooler (20, 22), in which the air squeezed by the air compressor (16, 18) can be cooled; an air dryer (40), the input end of the air dryer being connected to the output end of the at least one air cooler (20; 22); a cooling medium inlet opening (12), through which liquid cooling medium can be conveyed to the air cooler (20, 22); and a cooling medium outlet opening (14), through which heated cooling medium can be discharged, characterized in that: The silencer (43) has at least one regeneration air outlet opening (34) for discharging regeneration exhaust air (AL) guided through the silencer into the surrounding environment. When the drying medium (41) of the air dryer (40) is not regenerated, the at least one regeneration air outlet opening (34) is used as an air inlet (8*) for sucking ambient air (L) into the at least one air compressor (16, 18), and the ambient air (L) sucked through the silencer (43) can be guided to the at least one air compressor (16, 18) downstream after the silencer (43) through a suction line (DL).

20. A compressed air generating device (2.3, 2.4, 2.5, 2.6) comprising: at least one electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8*) through which ambient air (L) can be sucked in by means of the first air compressor (16); and an intercooler (20) and an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); an air dryer (40), wherein the input end of the air dryer is connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22); and a cooling medium delivery opening (14), through which the cooling medium delivery opening (15) is connected to the input end of the second air compressor (18). The outlet opening can discharge the heated cooling medium, and is characterized in that the silencer (43) has at least one regeneration air outlet opening (34), which is used to lead the regeneration exhaust gas (AL) guided through the silencer to the surrounding environment. When the drying medium (41) of the air dryer (40) is not regenerated, the at least one regeneration air outlet opening (34) is used to suck ambient air (L) into the air inlet end (8*) of the first air compressor (18), and the ambient air (L) sucked through the silencer (43) can be guided to the first air compressor (16) downstream after the silencer (43) through the suction line (DL).

21. A compressed air generating device (2.4) according to any one of the preceding claims, characterised in that A separator (88) for separating water and particles is arranged upstream of the silencer (43) or in the silencer, the separator being constructed and arranged in such a way that the ambient air (L) sucked in through at least one regeneration air outlet opening (34) serving as an air inlet (8*) can be cleaned of entrained water droplets and particles.

22. A compressed air generating device (2.5, 2.6), comprising: at least one electric motor (24); at least one air compressor (16, 18) that can be driven by the electric motor (24); an air inlet (8*), through which ambient air (L) can be sucked in by means of the air compressor (16, 18); at least one air cooler (20, 22), in which the air squeezed by the air compressor (16, 18) can be cooled; an air dryer (40), the input end of the air dryer being connected to the output end of the at least one air cooler (20, 22); a cooling medium inlet opening ( 12), liquid cooling medium can be delivered to the air cooler (20, 22) via the cooling medium inlet opening; a cooling medium outlet opening (14), heated cooling medium can be discharged via the cooling medium outlet opening; a multi-circuit protection valve (50), the multi-circuit protection valve pneumatically connecting the output end of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52); and a control and regulator (28), the control and regulator being connected to the multi-circuit protection valve (50) and a sensor arranged therein via at least one sensor line (56), characterized in that: The multi-circuit protection valve (50) can be separated from other components of the compressed air generating device and can be operated away from these components. The control and regulator (28) and the multi-circuit protection valve (50) have electrical connecting mechanisms (64, 68), which are connected to each other in a detachable manner via at least one flexible electrical line (56), and the multi-circuit protection valve (50) has a pneumatic connecting mechanism (62), which is at least indirectly connected to the output end of the air dryer (40) in a detachable manner via at least one flexible pneumatic line (DL5, 106).

23. A compressed air generating device (2.5, 2.6), comprising: at least one electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8*), through which ambient air (L) can be sucked in by means of the first air compressor (16); an intercooler (20) and an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); an air dryer (40), wherein the input end of the air dryer is connected to the output end of the aftercooler (22); a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22); a cooling medium outlet opening (14), through which heated cooling medium can be discharged; a multi-circuit protection valve (50), wherein the multi-circuit protection valve connects the output end of the air dryer (40) to at least one external compressed air storage tank (45) and an external The invention relates to a multi-circuit protection valve (50) and a compressed air consumer (51, 52) of the compressed air generating device. The multi-circuit protection valve (50) is pneumatically connected to the compressed air consumers (51, 52) of the compressed air generating device; and a control and regulator (28), which is connected to the multi-circuit protection valve (50) and the sensor arranged there via at least one sensor line (56), characterized in that the multi-circuit protection valve (50) can be separated from other components of the compressed air generating device and can be operated away from these components, the control and regulator (28) and the multi-circuit protection valve (50) have electrical connecting means (64, 68), which are connected to each other in a detachable manner via at least one flexible electrical sensor line (56), and the multi-circuit protection valve (50) has a pneumatic connecting means (62), which is at least indirectly connected to the output end of the air dryer (40) in a detachable manner via at least one flexible pneumatic line (DL5, 106).

24. The compressed air generating device (2.6) according to claim 22 or 23, characterized in that A dryer module (94) having the air dryer (40) has at least one electrical socket (100) and at least one pneumatic socket (104); the electrical socket (100) of the dryer module (94) is connected to an electrical socket (68) on a control and regulator (28) via the sensor line (56); an electrical plug of an electrical connection line (102) is detachably inserted into the electrical socket (100) of the dryer module (94); the electrical connection line (102) has a plug that can be detachably inserted into the multi-circuit protection valve (50). The pneumatic socket (104) of the dryer module (94) is pneumatically connected to a fifth compressed air line (DL5), and dry compressed air from the air dryer (40) can be guided through the fifth compressed air line. The plug of the pneumatic connecting line (106) can be detachably inserted into the pneumatic socket (104) of the dryer module (94), and the pneumatic connecting line (106) has a second plug that can be detachably inserted into the pneumatic socket (62) of the multi-circuit protection valve (50).

25. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: a control and regulator (28); at least one electric motor (24); at least one air compressor (16, 18) that can be driven by the electric motor (24); an air inlet (8, 8*), through which ambient air (L) can be sucked in with the aid of the air compressor (16, 18); at least one air cooler (20, 22), in which the air squeezed by the air compressor (16, 18) can be cooled; an air dryer (40), by means of which the compressed air can be dried; a cooling medium inlet opening (12), through which a liquid cooling medium can be supplied to the air cooler (20, 22); and a cooling medium outlet opening (14), through which the heated cooling medium can be discharged, characterized in that The control and regulation device (28) is an integral component of the inverter (26).

26. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: at least one electric motor (24), two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*), through which ambient air (L) can be sucked in by means of a first air compressor (16); an intercooler (20) and an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); and an air dryer (40), the input end of the air dryer is connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22). a cooling medium outlet opening (14) through which the heated cooling medium can be discharged; a multi-circuit protection valve (50) which pneumatically connects the output of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52); and a control and regulator (28) which is connected to the multi-circuit protection valve (50) and a sensor arranged therein via at least one sensor line (56), characterized in that the control and regulator (28) is an integrated component of the inverter (26).

27. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: at least one electric motor (24), two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*), through which ambient air (L) can be sucked in by means of a first air compressor (16); an intercooler (20) and an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); and an air dryer (40), the input end of the air dryer is connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22); and a cooling medium discharge opening (14), through which the heated cooling medium can be discharged; a multi-circuit protection valve (50), which pneumatically connects the output end of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52); and a control and regulator (28), which is connected to the multi-circuit protection valve (50) and a sensor arranged there via at least one sensor line (56), characterized in that the control and regulator (28) is an integrated component of the multi-circuit protection valve (50).

28. A compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9), comprising: a control and regulator (28); at least one electric motor (24); two air compressors (16, 18) which can be driven by the electric motor (24) and act in sequence; an air inlet (8, 8*) through which ambient air (L) can be sucked in by means of a first air compressor (16); an intercooler (20) and an aftercooler (22), wherein: The input end of the intercooler (20) is pneumatically connected to the output end of the first air compressor (16), wherein the output end of the intercooler (20) is pneumatically connected to the input end of the second air compressor (18), and wherein the output end of the second air compressor (18) is pneumatically connected to the input end of the aftercooler (22); and an air dryer (40), the input end of the air dryer is connected to the output end of the aftercooler (22); and a cooling medium inlet opening (12), through which liquid cooling medium can be delivered to the intercooler (20) and the aftercooler (22). ; and a cooling medium discharge opening (14), through which the heated cooling medium can be discharged; a multi-circuit protection valve (50), which pneumatically connects the output end of the air dryer (40) to at least one external compressed air reservoir (45) and external compressed air consumers (51, 52); and a control and regulator (28), which is connected to the multi-circuit protection valve (50) and a sensor arranged there via at least one sensor line (56), characterized in that the control and regulator (28) is an integrated component of the central vehicle controller (110).

29. Method for operating a compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) having the features of at least one of the device claims, wherein: Air compressed by means of at least one air compressor (16, 18) is cooled in at least one air cooler (20, 22), wherein the cooled compressed air is supplied to an air dryer (40) and dried there, wherein the dried compressed air is supplied to compressed air consumers (51, 52) and / or to at least one compressed air reservoir (45), and wherein, in order to regenerate a drying medium (41) arranged in the air dryer (40), a certain regeneration compressed air volume of dry compressed air is passed through the drying medium and subsequently discharged to the surrounding environment, characterized in that the regeneration compressed air volume required for regenerating the drying medium (41) is calculated at least in dependence on the temperature of the cooling medium before and / or after flowing through the air cooler (22) which is the last air cooler (22) arranged before the air dryer (40), and the regeneration compressed air volume of dry compressed air determined in this way is subsequently passed through the air dryer (40).

30. The method according to claim 29, characterized in that The first temperature sensor (73) measures the coolant temperature of the compressed air generating device (2) before the coolant inlet opening (12), and during a subsequent regeneration process, the regeneration compressed air volume required for drying the drying medium (41) in the air dryer (40) is guided through the air dryer (40) in a controlled and / or regulated manner depending on the measured coolant temperature.

31. The method according to claim 29, characterized in that The second temperature sensor (73') measures the coolant temperature upstream of the coolant inlet of the air cooler (22) which is the last air cooler arranged upstream of the air dryer (40) in the compressed air flow direction, and in dependence on the measured coolant temperature, during a subsequent regeneration process, conducts the regeneration compressed air volume required for drying the drying medium (41) in the air dryer (40) through the air dryer (40) in a controlled and / or regulated manner.

32. The method according to claim 29, characterized in that The coolant temperature after the coolant outlet of the air cooler (22) which is arranged as the last air cooler before the air dryer (40) in the compressed air flow direction is measured by means of a third temperature sensor (73"), and the regeneration compressed air volume required for drying the drying medium (41) in the air dryer (40) is guided through the air dryer (40) in a controlled and / or regulated manner during a subsequent regeneration process depending on the measured coolant temperature.

33. Method for operating a compressed air generating device (2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9) having the features of at least one of the device claims and having the features of at least one of the method claims 29 to 32, characterized in that The method has the following steps: a) sucking in ambient air by means of a first air compressor (16), b) pre-compressing the sucked ambient air to a first air pressure value in the first air compressor (16), c) cooling the intercooler (20) with a liquid cooling medium, d) cooling the pre-compressed compressed air in the intercooler (20), e) further compressing the compressed air to a second higher pressure value by means of a second air compressor (18), f) cooling the aftercooler (22) with a liquid cooling medium, wherein the aftercooler (22) is the first air cooler hydraulically reached by the cooling medium, as seen in the flow direction of the cooling medium, g) cooling the compressed air further compressed in the second air compressor (18) in the aftercooler (22), h) drying the cooled compressed air in an air dryer (40), i) forwarding the cooled and dried compressed air to compressed air consumers (51, 52) and / or at least one compressed air reservoir (45), j) transferring the liquid cooling medium from the aftercooler (22) to the intercooler (20), k) transferring the liquid cooling medium from the intercooler (20) to a cooling device (25) of the electric motor (24), 1) transferring liquid cooling medium from the cooling device (25) of the electric motor (24) to the cooling device (48) of the second air compressor (18), m) transferring liquid cooling medium from the cooling device (48) of the second air compressor (18) to the cooling device (27) of the inverter (26), n) transferring liquid cooling medium from the cooling device (27) of the inverter (26) to the cooling device (46) of the first air compressor (18), o) transferring liquid cooling medium from the cooling device (46) of the first air compressor (18) to an external cooling device (82).

34. The method according to any one of claims 29 to 33, characterized in that The time interval between two regeneration processes for drying a drying medium (41) of the air dryer (40) is controlled and / or regulated as a function of the temperature of the cooling medium at an output of the external cooling device (82) or at an input of the aftercooler (22).

35. The method according to any one of claims 29 to 34, characterized in that The time interval between two regeneration processes for drying a drying medium (41) of the air dryer (40) is controlled and / or regulated during a subsequent regeneration process as a function of the average ambient temperature.

36. The method according to any one of claims 29 to 34, characterized in that The respectively required regeneration compressed air volume for drying the drying medium (41) is controlled and / or regulated during a subsequent regeneration process as a function of the ambient temperature.

37. The method according to any one of claims 29 to 36, characterized in that The volume of regeneration compressed air respectively required for drying the drying medium (41) or the duration and / or frequency of the regeneration process are controlled and / or regulated as a function of the difference between the ambient temperature and the temperature of the cooling medium.

38. The method according to any one of claims 29 to 37, characterized in that In the case of unregulated control of the regeneration of the drying medium (41) of the air dryer (40), a maximum high temperature value of the cooling medium to be expected during operation of the compressed air production device (2.3, 2.4, 2.5, 26, 2.7) is determined, this value of the cooling medium temperature is used as a basis for determining a maximum regeneration compressed air volume, and a regeneration process for the drying medium (41) associated therewith is carried out using the maximum regeneration compressed air volume.

39. The method according to any one of claims 29 to 38, characterized in that The cooling medium from the cooling medium outlet of the intercooler (20) is conveyed to the cooling medium inlet of the electric motor (24) not directly but via a dryer module cooler (40.1), and the dryer module cooler (40.1) cools at least components of the air dryer (40).

40. The method according to any one of claims 29 to 38, characterized in that The temperature of the cooling medium is measured at the output end of the first external cooling device (82) or at the input end of the aftercooler (22), and when the measured temperature of the cooling medium reaches or exceeds a predetermined first upper limit value, the compressed air from the output end of the first air compressor (16) is no longer transported via the intercooler (20) but via the second external cooling device (120) to the input end of the second air compressor (18).

41. The method according to any one of claims 29 to 38, characterized in that The temperature of the cooling medium is measured at the output end of the first external cooling device or at the input end of the aftercooler (22), and when the temperature of the cooling medium reaches or exceeds a predetermined second limit value greater than the first limit value, the compressed air from the output end of the first air compressor (16) is no longer transported via the intercooler (20) but is transported to the input end of the second air compressor (18) via the second external cooling device (120), and then additionally, the compressed air from the output end of the second air compressor (18) is no longer transported via the aftercooler (22) but is guided to the output end of the aftercooler (22) or the input end of the air dryer (40) via the third external cooling device (122).

42. The method according to any one of claims 29 to 38, characterized in that Liquid cooling medium of the first external cooling device (82) is conducted through the cooling devices (25, 27, 46, 48) of the electric motor (24), of the inverter (26) and of the two air compressors (16, 18), even when no compressed air is conducted through the intercooler (20) and / or the aftercooler (22).

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