Compressor device, air spring system or sensor cleaning system and methods for their operation

Abstract

The invention relates to a compressor device (10), in particular a piston compressor, for a compressed air spring system and / or compressed air-based sensor cleaning system of a motor vehicle, wherein the compressor device (10) has a compressor housing (12) in which a first compressor unit (14) and a second compressor unit (16) are included. It is provided that the first compressor unit (14) and the second compressor unit (16) are fluidically separable from each other or are designed separately, wherein at least the first compressor unit (14) is designed to provide compressed air for a fluidically downstream or downstream compressed air unit (20), in particular an air spring gallery or a sensor cleaning gallery, in particular to feed compressed air into the compressed air unit (20), and wherein the second compressor unit (16) is designed at least to actively cool the compressor unit (10) independently of an external cooling circuit.

Description

[0001] The invention relates to a compressor device, in particular a piston compressor, for a compressed air spring system and / or compressed air-based sensor cleaning system of a motor vehicle, wherein the compressor device has a compressor housing comprising a first compressor unit and a second compressor unit. STATE OF THE ART

[0002] Compressor devices of the type mentioned above are generally known from the prior art.

[0003] Such a compressor device is, for example, a compressor for generating compressed air to fill the air springs of a motor vehicle or to supply sensors with compressed air for cleaning purposes as part of a sensor cleaning system.

[0004] Modern compressors are increasingly designed as two-stage compressors due to improved efficiency. Instead of a single compressor unit (typically a single piston cylinder), these compressors feature two mechanically interacting units. These units are usually fluidically and / or structurally coupled, allowing them to work synergistically. The two compressor units can be connected in parallel or in series for air compression. In a parallel configuration, both compressor units can compress a fluid simultaneously and supply it for different purposes.In a series circuit, air is typically drawn in from the environment by a first compressor unit, pre-compressed, and conveyed to a second compressor unit, which further compresses the pre-compressed air to the compressed air that is ultimately fed into the air springs.

[0005] Many applications of such two-stage compressors, particularly in pneumatic spring damper systems or pneumatic sensor cleaning systems, involve a significant amount of heat generation from the compressor itself or from the compression process of the fluid or compressed air. Essentially, compressed air is thermodynamically heated by the pressure build-up and the high volume flows involved in compression. Often, heat remains in the compressor, which is referred to as heat of compression. To ensure the compressor's continued operational reliability, it is therefore necessary to cool it and dissipate the generated heat. In particular, this heat generation reduces the performance of an air dryer commonly used in such applications, as its drying effect on compressed air decreases at high heat temperatures.

[0006] However, sufficiently strong cooling can rarely be provided by passive cooling, such as ambient air cooling or similar methods.

[0007] A well-known solution to this problem is to actively cool the compressor by connecting it to an external cooling circuit, such as the water cooling circuit of a vehicle that already has the compressor, thus utilizing an external cooling potential or coupling the compressor externally to it. However, coupling to the external cooling circuit often proves to be disadvantageous or not entirely satisfactory. For example, the coupling requirements may restrict the compressor to specific locations within the vehicle. In other words, the possible installation locations are severely limited by the spatial and mechanical constraints resulting from the coupling. Furthermore, there is always a dependency on the functionality of the external cooling circuit. If it malfunctions or becomes partially malfunctioning for any reason, the compressor cannot be adequately cooled and may fail.Its lifespan is shortened. Therefore, a malfunction of the external cooling circuit typically results in the compressor becoming inoperable or at least operating with limited functionality; problems in the cooling circuit always affect the compressor. Ultimately, the external cooling circuit must be structurally dimensioned and designed with sufficient capacity to adequately cool the compressor in addition to its intended function and the standard components requiring cooling. This results in increased manufacturing and operating costs, particularly regarding energy efficiency.

[0008] The object of the invention is therefore to provide an improved solution with regard to the disadvantages discussed above.

[0009] This problem is solved by a compressor device, a system, and a method according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims. REVELATION OF THE INVENTION

[0010] The invention relates to a compressor device, in particular a piston compressor, for a compressed air spring system and / or compressed air-based sensor cleaning system of a motor vehicle, wherein the compressor device has a compressor housing in which a first compressor unit and a second compressor unit are included.

[0011] In other words, the compressor device is, as discussed at the beginning, designed in two stages or with two compressor units.

[0012] According to the invention, it is provided that the first compressor unit and the second compressor unit are fluidically separable from each other or are designed to be separate, wherein at least the first compressor unit is designed to provide compressed air for a fluidically downstream or downstream compressed air unit, in particular an air spring gallery or a sensor cleaning gallery, in particular to feed it into the compressed air unit, and wherein the second compressor unit is designed at least to actively cool the compressor unit independently of an external cooling circuit.

[0013] Thus, the compressor device designed according to the invention has its own cooling function or is designed to actively cool itself independently, i.e., to dissipate the heat it produces. In this context, with respect to known two-stage compressor devices, the first compressor unit represents the first stage, and the second compressor unit represents the second stage. The two stages can be operated in series or in parallel. In any case, the two compressor stages or units do not work together to fulfill a single function (generally compressed air generation). Instead, the two compressor units have different, more precisely, separate or independent functions. In this respect, the compressor units are fluidically separated from one another or at least separable, and in particular, structurally separated from one another within the compressor housing.In this configuration, the first stage or first compressor unit fulfills the function of compressed air generation, or is designed to do so, while the second stage or second compressor unit fulfills the function of actively cooling the entire compressor assembly. The drive for both compressor units can be mechanically unified or independent.

[0014] Therefore, according to the invention, no connection to an external cooling circuit is required. Due to its ability to cool itself independently, the compressor is independent of external cooling circuits, particularly their operational reliability.

[0015] Advantageously, the compressor device according to the invention is thus resistant to malfunctions, and its operational capability can be reliably guaranteed. Furthermore, it advantageously offers a wide range of possibilities regarding potential installation locations.

[0016] According to a preferred embodiment, the first compressor unit and the second compressor unit can be designed as structurally separate compressors, in particular with separate mechanical drives, especially separate electric motors. The compressor units can be operated independently of each other or remain operational at least temporarily in the event of a malfunction of the other compressor unit. Advantageously, this further increases operational reliability.

[0017] According to a preferred embodiment, the first compressor unit and the second compressor unit are designed as two-stage piston compressors or two-stage diaphragm compressors with a common mechanical drive, in particular an electric motor, wherein a first compressor stage of the first compressor unit is assigned to compress compressed air and a second compressor stage of the second compressor unit is assigned to compress and / or convey coolant. The respective compressor stage constitutes the corresponding compressor unit or is at least a part thereof. The common drive of the compressor units offers the advantage of simplifying the design of the compressor device and thereby reducing its manufacturing costs.

[0018] According to a preferred embodiment, at least one of the compressor units, and in particular both compressor units, can be designed as a cylindrical piston compressor with a piston element, especially a double piston element, movable within a cylindrical piston chamber. The piston chamber can be located within the compressor housing or have its own separate cylindrical housing. Optionally, both compressor units can be of the same design. This further simplifies the construction and manufacturing of the compressor unit. Moreover, the compressor unit exhibits particularly high robustness and thus operational reliability.

[0019] According to a preferred embodiment, the compressor assembly may include a cooling circuit with a closed piping system, wherein the second compressor assembly is configured to circulate a liquid and / or gaseous refrigerant, in particular a hydrocarbon-based refrigerant, water, or air, through the cooling circuit for active cooling. The cooling circuit is an integral part of the compressor assembly. In particular, the cooling circuit is arranged or configured at least partially within the compressor housing. Advantageously, the cooling circuit represents a mechanically simple, robust, and therefore cost-effective means of dissipating the heat generated by the compressor assembly. In addition to water or air, hydrocarbon-based refrigerants, in particular hydrocarbons, may preferably be used as refrigerants.Hydrofluorocarbon-based refrigerants (HFCs), or refrigerants based on methane or propane, such as R134a, R32, R290 or R410a, can be used advantageously.

[0020] According to a preferred embodiment, the compressor unit may include an at least partially integrated heat pump, in particular the cooling circuit unit being designed as a heat pump, with the second compressor unit being designed as the heat pump compressor of the heat pump. The compressor unit constitutes a part of the heat pump or provides a portion thereof. "Integrated" in this context means at least functionally coupled, but structurally combined, or integrated in a single housing. The heat pump compressor circulates the refrigerant of the heat pump. For example, the heat pump is formed with a heat exchanger integrated in the compressor housing, comprising an evaporator side for cooling the compressor unit and a condenser side, separated from the evaporator side by a throttle, for dissipating the waste heat by means of compressed refrigerants to actively cool the compressor unit.Advantageously, this provides a particularly efficient solution for active cooling in terms of cooling potential and energy consumption.

[0021] According to a preferred embodiment, the cooling circuit assembly comprises at least one evaporator side, forming a heat absorption area at least partially within the compressor housing, and one condenser side, forming a heat dissipation area at least partially on an outer surface of the compressor housing. The refrigerant is circulated within the piping system between at least the heat dissipation area (the condenser side) and, separated by a throttle, the heat absorption area (the evaporator side) of the cooling circuit assembly by means of the second compressor assembly. The refrigerant can be pumped through the piping system from the heat absorption area to the heat dissipation area and back again by means of the second compressor assembly. In particular, a heat pump is implemented, at least in its basic form. Advantageously, this is a mechanically simple yet efficient solution.

[0022] According to a preferred embodiment, the heat dissipation area can be designed as an ambient air cooler or ambient air heat exchanger, in particular with an actively operated cooling fan, and / or as a cooling section or cooling fin surface formed at least partially on the outside of the compressor housing. The cooling section / heat exchange surface is formed integrally with the compressor housing, or at least partially. In particular, the heat dissipation area has its own drive device for actively removing the heat. Advantageously, this provides a simple and cost-effective, yet sufficiently efficient solution for ensuring adequate heat dissipation.

[0023] According to a preferred embodiment, the compressor device, in particular the cooling circuit, may include a vortex tube, and in particular, a heat dissipation section may be designed as a vortex tube. The operating principle of a vortex tube is generally known. By means of the vortex tube, heat contained in an airflow can be dissipated (passively) by splitting the airflow into a warm and a cold partial flow. The warm partial flow is discharged to the atmosphere or environment, and the cold partial flow can be returned to the heat source for reheating. The corresponding coolant can be compressed air. In the present case, the compressed air, acting as a coolant, is conveyed by means of the second compressor device through the compressor device to absorb the generated heat and then to the vortex tube for heat dissipation. The vortex tube serves as the heat dissipation device.In particular, the second compressor unit circulates the air between a heat absorption area located inside the compressor housing and the vortex tube. The corresponding warm partial flow, and thus the heat previously absorbed by the compressor unit, is separately discharged to the outside by the vortex tube, while the cold partial flow is returned. The vortex tube can be located inside the compressor housing (with a corresponding discharge line to the outside) or outside of it. Advantageously, this provides an efficient and reliable cooling solution.

[0024] In a secondary aspect, the invention relates to an air spring system or sensor cleaning system with a compressed air device, in particular an air spring gallery or sensor gallery, which can be filled with compressed air, and with a compressor device for generating the compressed air. According to the invention, it is proposed that the compressor device be designed as described above. The advantages already mentioned in advance arise in this respect.

[0025] In a further subordinate aspect, the invention relates to a method for operating a compressor device, in particular the compressor device according to the invention, or a compressed air spring system or compressed air-based sensor cleaning system, in particular the air spring system or sensor cleaning system according to the invention, wherein the compressor device has a compressor housing and is designed with a first compressor unit and a second compressor unit.According to the invention, it is proposed that the respective functions of the first compressor unit and the second compressor unit are fluidically separated from one another, wherein the first compressor unit provides compressed air for a fluidically downstream or downstream compressed air unit, in particular an air spring gallery or sensor cleaning gallery, and in particular feeds compressed air into the compressed air unit, and wherein the second compressor unit actively cools at least the compressor unit independently of an external cooling circuit. The advantages already mentioned above result from this.

[0026] According to a preferred further development, it can be provided that a heat pump of the compressor unit is operated for active cooling by means of the second compressor unit. The advantages already mentioned in advance result from this.

[0027] According to a preferred embodiment, for active cooling by means of the second compressor unit, a liquid and / or gaseous refrigerant, in particular a hydrocarbon-based refrigerant, water, or air, is circulated within a closed piping system of the cooling circuit between at least one heat dissipation area (condenser side), located particularly on the outside of the compressor housing, and at least one heat absorption area (evaporator side), separated from the heat dissipation area by a throttle valve, within the compressor housing. In addition to water or air, hydrocarbon-based refrigerants, in particular hydrofluorocarbon-based refrigerants (HFCs), or refrigerants based on methane or propane, such as R134a, R32, R290, or R410a, can preferably be used as refrigerants.Cooling, i.e., the removal of the heat generated by the compressor unit, is achieved by actively circulating the refrigerant through the compressor unit or its second compressor unit. This results in the advantages already mentioned above.

[0028] According to a preferred embodiment, the heat generated by the compressor device can be dissipated to the surrounding air or atmosphere via the heat dissipation area, in particular as a cooler or heat exchanger, preferably with an actively operated cooling fan, and / or at least partially via a cooling section or cooling fin surface formed on the outside of the compressor housing. This results in the advantages already mentioned above.

[0029] According to a preferred further development, it can be provided that a vortex tube of the compressor unit is operated for active cooling by means of the second compressor unit. The advantages already mentioned in advance result from this.

[0030] According to a preferred embodiment, the first compressor unit and the second compressor unit can be operated simultaneously and / or synchronously by means of a mechanical and / or electrical drive of the compressor unit. This results in the advantages already mentioned above. DRAWINGS

[0031] Further advantages become apparent from the accompanying drawing description. The drawings illustrate exemplary embodiments of the invention. The drawing, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0032] They show: Fig. 1 A simplified schematic representation of an advantageous compressor device according to a first embodiment, and Fig. 2 A simplified schematic representation of the compressor device according to a second embodiment.

[0033] In the figures, similar elements are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0034] Fig. Figure 1 shows a simplified schematic circuit diagram of an advantageous compressor device 10. When used as intended, the compressor device 10 is part of a compressed air spring system and / or a compressed air-based sensor cleaning system of a motor vehicle. In this case, the compressor device 10 is designed as a piston compressor.

[0035] The compressor device 10 is a so-called two-stage piston compressor. In this context, the compressor device 10 has a compressor housing 12 in which a first compressor unit 14 is arranged as the first stage and a second compressor unit 16 as the second stage. Thus, the compressor units 14 and 16 are enclosed within the compressor housing 12.

[0036] The compressor units 14, 16 are designed as structurally separate compressors. Each compressor unit, 14, 16, is a cylindrical piston compressor with a piston element movable within a cylindrical piston chamber. The respective piston chambers are thus arranged within the same compressor housing 12, but are structurally separated from each other fluidically, for example by a partition.

[0037] To operate the compressor unit 10 or the compressor units 14, 16, the compressor unit 10 has a mechanical drive 18. It is provided that both the first compressor unit 14 and the second compressor unit 16 can be driven jointly, and in particular synchronously, by the same drive 18. In other words, the mechanical drive 18 is assigned to both the first compressor unit 14 and the second compressor unit 16. The mechanical drive 18 is designed as an electric motor.

[0038] Basically, the main function of the compressor device 10 is to provide compressed air for a fluidically downstream or downstream compressed air device 20, in particular an air spring gallery or a sensor cleaning gallery, and preferably to feed it into the compressed air device 20.

[0039] It is known that a considerable amount of heat is generated during such intended operation. To dissipate this heat and prevent overheating of the compressor unit 10, thereby ensuring its continued intended operation, in particular the drying function of an air dryer, it is necessary to reliably cool the compressor unit 10. In compressor units known from the prior art, this cooling is typically achieved by connecting the compressor unit to an external cooling system.

[0040] In contrast, the present compressor device 10 advantageously features self-cooling. Therefore, in addition to generating compressed air, the compressor device 10 is designed to actively cool itself independently of an external cooling circuit.

[0041] For this purpose, it is advantageously provided that the first compressor unit 14 and the second compressor unit 16 are, as already mentioned, fluidically and preferably structurally and thus functionally separated from one another. In this context, the first compressor unit 10 fulfills the primary purpose of compressed air generation. The second compressor unit 16, on the other hand, is designed to actively cool the compressor unit 10 as a whole by providing at least a partial cooling function.

[0042] The fluidic or structural and functional separation of the compressor units, 14, 16 is in Fig. Figure 1 illustrates this clearly. Air from the atmosphere can be drawn in via an air inlet 23 by means of the first compressor unit 14 and compressed into compressed air. The generated compressed air can then be supplied to the compressed air unit 20, whereby the supply of compressed air can be controlled by a valve unit 24 fluidically upstream of the compressed air unit 20. Several, in this case two, check valves 26 are also provided to control the flow direction of the air or compressed air. The first compressor unit 14, together with the compressed air unit 20 and the air inlet 23, forms a compressed air circuit system.

[0043] The compressor unit 10 further comprises a cooling circuit unit 28 associated with the second compressor unit 16, which is structurally and functionally independent or separate from the compressed air circuit unit formed by the first compressor unit 14. The cooling circuit unit 28 has a closed piping system, wherein a coolant is conveyed or circulated through the cooling circuit unit 28 or its piping system for active cooling by means of the second compressor unit 16.

[0044] At the in Fig. In the first embodiment shown in Figure 1, the compressor device 10 has a heat pump that is at least partially integrated, wherein the second compressor unit 16 is designed as the heat pump compressor of this heat pump. The cooling circuit unit 28 is part of the heat pump, wherein a refrigerant that is liquid at least in its initial state, in particular a (fluoro)hydrocarbon-based refrigerant, (compressed) air or water, is circulated through the corresponding piping system.

[0045] In this circulation, the coolant is conveyed from an evaporator side 30, which forms a heat absorption area, to a condenser side 32, which forms a heat emission area. A throttle 34 is arranged between the evaporator side 30 and the condenser side 32 to control the fluid flow and / or vapor pressure of the coolant. The evaporator side 30, condenser side 32, and throttle 34 are components of the cooling circuit assembly 28, which can be operated by means of the second compressor assembly 16. Furthermore, several check valves 26 are provided to control the fluid flow of the coolant.

[0046] In the area of ​​the evaporator side 30, the heat generated by the compressor device 10 is absorbed by the refrigerant through evaporation. The absorbed heat is released to the environment in the area of ​​the condenser side 32 through condensation, as shown in Fig. 1 is indicated by arrows. For this purpose, the evaporator side 30 or the heat dissipation area is formed or arranged at least partially on an outer surface of the compressor housing 12. For example, the heat dissipation area can be designed as a cooling section or cooling fin surface formed at least partially on the outside, or it can be formed by an ambient air cooler or ambient air heat exchanger arranged on the outside of the compressor housing 12.

[0047] Fig. 2 shows the previously mentioned Fig. 1. Compressor device 10 according to a second embodiment. Identical elements are shown with the same reference numerals, and only the differences are explained below.

[0048] The in Fig. The second embodiment of the compressor device 10 shown in Figure 2 differs from the one shown based on Fig.1 first embodiment discussed in the fact that the cooling of the compressor device 10 is effected not by the at least partially integrated heat pump, but by a vortex tube 36.

[0049] The structure and function of a vortex tube are known in principle. In this case, it is provided that, for cooling purposes, air is circulated as a coolant within the cooling circuit 28 between a heat absorption area 38 and the vortex tube 36 by means of the second compressor unit 16.

[0050] Here, the heat generated by the compressor unit 10 is absorbed by the air in the heat absorption area 38, thereby heating it. The heated air is conveyed by the second compressor unit 16 to an inlet side 40 of the vortex tube 36. Within the vortex tube 36, the corresponding airflow fed into the vortex tube 36 at the inlet side 40 is split into a warm airflow 42 and a cold airflow 44 due to the known vortex tube effect.

[0051] The warm airflow 43, and thus the heat previously absorbed by the air and generated by the compressor unit 10, is discharged from the vortex tube 36 via an outlet 46 into the environment. The cold airflow 44, on the other hand, is directed back to the heat absorption area 38 to absorb further heat or is returned by means of the second compressor unit 16. By splitting the incoming airflow using the vortex tube 36, the heat can be efficiently dissipated to the environment, thus actively cooling the compressor unit 10.

[0052] The compressor device 10 discussed above advantageously has an independent, actively operable cooling function and is independent of otherwise necessary external cooling systems. The compressor device 10 fulfills its intended primary purpose of generating compressed air and simultaneously provides an advantageous independent cooling function. Reference symbol list 10 Compressor device 12 compressor housings 14 First compressor unit 16 Second compressor unit 18 Drive 20 Compressed air equipment 22 Air intake 24 Valve assembly 26 Check valve 28 Cooling circuit device 30 evaporator side 32 Capacitor side 34 Throttle 36 Vortex tube 38 Heat absorption area 40 Entrance page 42 Warm airflow 44 Cold airflow 46 Outlet

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