Compressor device for delivering compressed fluids

Abstract

The present invention relates in particular to a compressor device (100) for delivering compressed fluids, in particular liquefied fuels for rocket engines, comprising: at least one first compressor unit (102a) for delivering at least one first compressed fluid (F1), which first compressor unit comprises a first compressor housing (104) and at least one first rotating compressor element (106), wherein the at least one first rotating compressor element (106) is rotatably mounted in the first compressor housing (104) by means of a first compressor bearing (108); and a drive unit (110) for driving the at least one first compressor unit (102a), wherein the drive unit (110) comprises a drive unit housing (112) and a rotating drive element (114), wherein the rotating drive element (114) is rotatably mounted in the drive unit housing (112) by means of a drive bearing (116).

Description

[0001] Compressor device for conveying compressed fluids

[0002] The present invention relates to a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines. Rocket engines within the meaning of this invention serve, in particular, to propel manned or unmanned rockets so that they reach their intended destination in space (e.g., the International Space Station ISS or the like) safely, efficiently, and quickly. In order to provide the rocket engines with the intended propellants, in particular cryogenic ones, powerful compressor devices are required that generate the necessary pressure in the combustion chamber of the rocket engine and deliver the propellants to the injection head of the combustion chamber.

[0003] Such compressor or pump systems can be designed, in particular, as turbomachines (which can be axial and / or radial compressors) with high power output at high mass flows of 5 to over 100 kg / s and high pressure rises of over 200 bar, thus possessing a high power density. Furthermore, they typically operate with cryogenic propellants as the pumping medium. In other words, these compressor systems are subject to extreme thermomechanical and fluid-dynamic demands. Therefore, system simplifications always offer the prospect of greater operational safety, reliability, and service life expectancy.

[0004] Such compressor devices are already known from the prior art. EP 0 530 573 A1, for example, discloses a turbopump assembly comprising a housing for a first pump section, a housing for a second pump section, and a common rotatable shaft disposed within the housings, which further define first and second pump sections. The housings and the rotatable shaft also define internal distribution lines selectively positioned within the first pump section and the second pump section, whereby the first pump section, the second pump, and the internal distribution lines form an integrated turbine and dual pump configuration.

[0005] When using radial compressors, the radial operating loads can lead to deflection of the central shaft, which should have the smallest possible shaft diameter and bearing diameter to achieve improved compressor efficiency. However, this requirement runs counter to the goal of achieving the largest possible bending moment of the shaft, which is necessary to keep shaft deflection as low as possible. Furthermore, the stringent requirements for bearings, lubrication, and sealing of the shaft components require a sometimes very complex design approach to the application of the corresponding machine elements, resulting in a complex and cost-intensive overall design of the state-of-the-art compressor systems.

[0006] The present invention is therefore based on the object of providing, in particular, a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, which preferably promises a simplified structure, lower manufacturing costs and higher operational reliability.

[0007] This object is achieved according to the invention by the features of independent claim 1. Advantageous developments of the invention are described in the dependent claims.

[0008] A compressor device according to the invention for conveying compressed fluids, in particular liquefied propellants for rocket engines, comprises:

[0009] - at least one first compressor unit for conveying at least one first compressed fluid, comprising a first compressor housing and at least one first rotating compressor element, wherein the at least one first rotating compressor element is rotatably mounted in the first compressor housing by means of a first compressor bearing; and

[0010] - a drive unit for driving the at least one first compressor unit, wherein the drive unit comprises a drive unit housing and a rotating drive element, wherein the rotating drive element is rotatably mounted in the drive unit housing by means of a drive bearing.

[0011] The first compressor housing and the drive unit housing can be designed as two separate housings. Both housings can be secured together by positive-locking connection areas. Housing shoulders, housing projections, and corresponding housing grooves or housing recesses can be provided as positive-locking connection areas. Additionally or alternatively, both housings can also be secured together by means of friction-locking fastening elements such as screws.

[0012] Furthermore, it can be provided additionally or alternatively that both housings can also be connected to each other via a material connection such as a welded connection or a soldered connection.

[0013] Alternatively, it may be provided that the first compressor housing and the drive unit housing can be designed as a one-piece housing.

[0014] It can further be provided that the rotating drive element and the at least one first rotating compressor element are connected to one another in a rotationally fixed manner in the assembled state.

[0015] The rotating drive element and the at least one first rotating compressor element can each be designed as rotationally symmetrical elements. The rotating drive element and the at least one first rotating compressor element can be fastened or connected to one another by form-fitting connecting areas.

[0016] As positive connection areas, corresponding projections and corresponding grooves or recesses for mutual engagement can be provided. Examples of these could be key connections, toothed connections, wedge connections, or pin connections.

[0017] Additionally or alternatively, the rotating drive element and the at least one first rotating compressor element can also be fastened to one another by means of frictional fastening elements such as screws.

[0018] Furthermore, it can be provided additionally or alternatively that the rotating drive element and the at least one first rotating compressor element can also be connected to one another via a material connection such as a welded connection or soldered connection.

[0019] Alternatively, it can be provided that the rotating drive element and the at least one first rotating compressor element can be designed as a single, integral rotating element. The compressor device can further comprise a second compressor unit for conveying a second compressed fluid, which comprises a second compressor housing and a second rotating compressor element.

[0020] The second compressor housing can be connected to the drive element housing either indirectly, i.e., via the first compressor housing, or attached. This connection can be configured in a manner similar to the connection between the first compressor housing and the drive unit housing.

[0021] Alternatively, the second compressor housing may be directly connected to the drive element housing, which may be connected to the first compressor housing as described above.

[0022] The second compressor housing and the drive unit housing can be designed as two separate housings. Both housings can be secured together by positive-locking connection areas. Housing shoulders, housing projections, and corresponding housing grooves or housing recesses can be provided as positive-locking connection areas. Additionally or alternatively, both housings can also be secured together by means of frictional fastening elements such as screws.

[0023] Furthermore, it can be provided additionally or alternatively that both housings can also be connected to each other via a material connection such as a welded connection or a soldered connection.

[0024] Alternatively, it may be provided that the second compressor housing and the drive unit housing can be designed as a one-piece housing.

[0025] The second rotating compressor element can be rotatably mounted in the second compressor housing by means of a second compressor bearing, and wherein the rotating drive element and the second rotating compressor element can be connected to one another in a rotationally fixed manner in the assembled state.

[0026] If the second compressor unit can be provided additionally and consequently the second rotating compressor element can be rotatably mounted in the second compressor housing by means of the second compressor bearing, the drive bearing can only be provided optionally or can be omitted in order to avoid overdeterminations in the first and second compressor bearings.

[0027] The rotating drive element and the second rotating compressor element can each be configured as rotationally symmetrical elements. The second rotating compressor element can be connected to the rotating drive element either indirectly, i.e., by means of the at least one first rotating compressor element. This connection can be configured in a manner corresponding to the connection between the at least one first rotating compressor element and the rotating drive element.

[0028] Alternatively, the second rotating compressor element may be directly connected to the rotating drive element, which may be connected to the at least one first rotating compressor element as described above.

[0029] The rotating drive element and the second rotating compressor element can therefore be fastened or connected to each other by form-fitting connecting areas.

[0030] As positive connection areas, corresponding projections and corresponding grooves or recesses for mutual engagement can be provided. Examples of these could be key connections, toothed connections, wedge connections, or pin connections.

[0031] Additionally or alternatively, the rotating drive element and the second rotating compressor element can also be fastened to one another by means of frictional fastening elements such as screws.

[0032] Furthermore, it can be provided additionally or alternatively that the rotating drive element and the second rotating compressor element can also be connected to one another via a material connection such as a welded connection or a soldered connection.

[0033] Alternatively, the rotating drive element and the second rotating compressor element may be formed as a single, integral rotating element. The rotating drive element may have a central cavity extending axially along the center axis of the compressor device.

[0034] Additionally or alternatively, it can be provided that the at least one first rotating compressor element has a central cavity extending axially along the center axis of the compressor device.

[0035] Furthermore, additionally or alternatively, it can be provided that the second rotating compressor element has a central cavity extending axially along the central axis of the compressor device.

[0036] Particularly advantageously, it can be provided that the rotating drive element, the at least one first rotating compressor element and the second rotating compressor element can each have a central cavity extending axially along the central axis of the compressor device.

[0037] Each of these cavities can, in particular, be designed to be rotationally symmetrical.

[0038] Additionally or alternatively, the rotating drive element, the at least one first rotating compressor element and the second rotating compressor element may preferably have a common cavity.

[0039] The common cavity can be designed as an uninterrupted or continuous cavity which, in the assembled state, can be composed of the central cavity of the rotating drive element, the at least one first rotating compressor element and the second rotating compressor element.

[0040] The cavity of the rotating drive element can have a larger cross-sectional area oriented perpendicular to the center axis of the compressor device than the cavity of the at least one first rotating compressor element.

[0041] These two cross-sectional areas can each be arranged in at least one axial section of the cavity within its entire axial extent (along the center axis of the compressor device) of the rotating drive element and of the at least one first rotating compressor element. Additionally or alternatively, it can be provided that the cavity of the rotating drive element can have a larger cross-sectional area, oriented perpendicular to the center axis of the compressor device, than the cavity of the second rotating compressor element.

[0042] These two cross-sectional areas can each be arranged in at least one axial section of the cavity within its entire axial extent (along the center axis of the compressor device) of the rotating drive element and the second rotating compressor element. In other words, "axial" can describe a direction running along or along the center axis, and "radial" can describe a direction perpendicular to the center axis.

[0043] By means of this larger cross-sectional area in at least one axial section of the cavity, the rotating drive element can have a maximum bending moment of resistance there, so that the deflection of the rotating drive element can be minimized. Deflection can be minimized in particular if the drive bearing can be omitted, as explained above.

[0044] It may further be provided additionally or alternatively that the rotating drive element is mounted directly in the drive unit housing.

[0045] Additionally or alternatively, it can be provided that the at least one first rotating compressor element is mounted directly in the first compressor housing.

[0046] Additionally or alternatively, it can be provided that the second rotating compressor element can be mounted directly in the second compressor housing.

[0047] In other words, the two rotating compressor elements and optionally the rotating drive element can form a common rotor for the compressor device through their respective direct compressor or drive bearings. Thus, in particular, the two rotating compressor elements and the rotating drive element can be mounted in the first compressor housing, the drive unit housing, and the second compressor housing without a drive shaft and / or compressor shaft. This advantageously eliminates the need for a conventional shaft (as in the prior art), which is manufactured separately and connected to functional components of the compressor unit. Consequently, the function of the shaft can be inherently assumed, for example, by the two rotating compressor elements and optionally additionally by the rotating drive element.

[0048] The first compressor bearing can be arranged on a radially outer surface of the at least one first rotating compressor element.

[0049] Additionally or alternatively, the drive bearing can be arranged on a radially outer surface of the rotating drive element.

[0050] Additionally or alternatively, it can be provided that the second compressor bearing is arranged on a radially outer surface of the second rotating compressor element.

[0051] By means of the first compressor bearing and the drive bearing, a fixed-loose bearing for the at least one first rotating compressor element and the rotating drive element can be formed.

[0052] In addition, this fixed-loose bearing can be additionally designed for the second rotating compressor element by means of the second compressor bearing.

[0053] Alternatively, it can be provided that a fixed-loose bearing for the second rotating compressor element and the rotating drive element can be formed by means of the second compressor bearing and the drive bearing.

[0054] The options for the fixed-loose bearing arrangement described above can also be implemented using an inclined bearing arrangement. The bearing surfaces of the first and / or second compressor bearing arrangement required for the inclined bearing arrangement can each have an inherent bearing plane, which can be aligned parallel, perpendicular, and / or obliquely (i.e., by means of an included angle between greater than 0° and less than 90°) to the center axis of the compressor device.

[0055] The first compressor bearing may comprise one or more rolling bearings. Additionally or alternatively, the second compressor bearing may comprise one or more rolling bearings.

[0056] Additionally or alternatively, the drive bearing may comprise one or more rolling bearings.

[0057] Additionally or alternatively, it may be provided that the first compressor bearing may comprise one or more plain bearings.

[0058] Additionally or alternatively, the second compressor bearing may comprise one or more plain bearings.

[0059] Additionally or alternatively, the drive bearing may comprise one or more plain bearings.

[0060] The one or more plain bearings may preferably comprise ceramic fiber composite plain bearings (hereinafter: CMC plain bearings).

[0061] The CMC plain bearings can be designed as plain bearing sleeves and can have a fiber-reinforced, porous ceramic structure. The fibers are preferably carbon fibers, although other suitable fiber materials can also be used. Thanks to the porous ceramic structure, the CMC plain bearings can store a certain amount of lubricant and release it to the surrounding housing or compressor element parts in the form of transpiration lubrication.

[0062] CMC plain bearings can feature the following material combinations (fiber material / ceramic structure or matrix structure): C / SiCN, C / SiCO, C / CSiC, and / or C / C. Oxipol can be provided additionally or alternatively as a ceramic structure or matrix structure, for example, with carbon (C) as the fiber material. Oxipol is a so-called O-CMC, i.e., an oxide fiber composite material that is also oxidation-resistant and thus also suitable for use in oxygen-based oxidizing environments.

[0063] The aforementioned CMC plain bearings should be designed so that, after appropriate pretreatment, they no longer release fine matrix or fiber particles of critical size during use. Furthermore, they should exhibit a certain degree of mechanical compliance (low rigidity), coupled with the property of providing a friction-minimized friction pairing with the preferably metallic first rotating compressor element, the rotating drive element, and / or the second rotating compressor element. Furthermore, the CMC plain bearings should ensure low breakaway torques.

[0064] During the manufacturing process of the porous CMC material, a permeability that can be adjusted within certain limits can be imposed to allow flow through the composite of fiber material / matrix structure by controlling the material porosity. The permeability, which can be discretely measured in all orthotropic directions on corresponding laboratory samples, can be quantified using permeability coefficients kd and kf (Darcy-Forchheimer coefficients).

[0065] CMC plain bearings exhibit particularly low thermal expansion, making them resistant to very high temperature gradients and durable. They are also highly thermal shock-resistant and quasi-ductile compared to monolithic ceramics, making them significantly less susceptible to fracture.

[0066] It can further be provided that the first compressor housing has a first return channel extending from a high-pressure region of the first compressor housing to the first compressor bearing. Consequently, a partial mass flow of the at least one first compressed fluid can be supplied to the first compressor bearing for its lubrication and / or cooling.

[0067] After the partial mass flow of the first compressed fluid has flowed through the first compressor bearing, it can be introduced into an intake area of ​​the first compressor housing.

[0068] Additionally or alternatively, the drive unit housing can have one or more return channels extending from a high-pressure region of the first compressor housing and / or the second compressor housing to the drive bearing. Consequently, a partial mass flow of the at least one first compressed fluid and / or the second fluid can be supplied to the drive bearing for its lubrication and / or cooling.

[0069] In other words, the high-pressure regions of the first compressor housing and the second compressor housing can be connected to each other via one or more return channels. The partial mass flow(s) of the first and / or second compressed fluid that has flowed through the drive bearing can flow into one or the other high-pressure region depending on the pressure gradient of the two high-pressure regions. Alternatively, it can also be provided that the drive bearing can be sealed in the case of two different fluids to be compressed, so that no connection can occur between the two high-pressure regions.

[0070] In the event that the drive bearing cannot be provided, the high-pressure areas of the first compressor housing and the second compressor housing can be connected to each other via a connecting channel or connecting gap in the drive unit housing.

[0071] Additionally or alternatively, the second compressor housing can have a second return channel extending from a high-pressure region of the second compressor housing to the second compressor bearing. This allows a partial mass flow of the second compressed fluid to be supplied to the second compressor bearing for its lubrication and / or cooling.

[0072] After the partial mass flow of the second compressed fluid has flowed through the second compressor bearing, it can be introduced into an intake area of ​​the second compressor housing.

[0073] Furthermore, it can be provided that the at least one first rotating compressor element comprises a plurality of blades whose outer ends are connected by a first closed casing.

[0074] An outer surface of this closed casing can form the above-mentioned casing surface, which has at least one bearing area for the first compressor bearing.

[0075] In other words, the radially outer ends of the blades can be geometrically described by an envelope curve or locus curve, from which the shape of the closed casing can result due to the rotationally symmetrical structure of the first rotating compressor element. The at least one bearing region can be formed by one or more flat or straight surface regions on the casing surface. Additionally or alternatively, the second rotating compressor element can comprise a plurality of blades whose outer ends are connected by a second closed casing.

[0076] An outer surface of this closed casing can form the above-mentioned casing surface, which has at least one bearing area for the second compressor bearing.

[0077] In other words, the radially outer ends of the blades of the second rotating compressor element can be geometrically described by an envelope curve or locus curve, from which the shape of the closed casing can result due to the rotationally symmetrical structure of the first rotating compressor element. The at least one bearing region can be formed by one or more flat or straight surface regions on the casing surface.

[0078] It can be provided that the first compressor housing comprises a first labyrinth seal for its sealing.

[0079] The first labyrinth seal can be arranged between the first compressor housing and the at least one first rotating compressor element and have a leakage mass flow of the at least one first compressed fluid that can be fed to the first return channel.

[0080] Additionally or alternatively, the second compressor housing may comprise a second labyrinth seal for sealing the second compressor housing, which is arranged between the second compressor housing and the second rotating compressor element and which has a leakage mass flow of the second compressed fluid that can be fed to the second return channel.

[0081] The first and second labyrinth seals can be formed by means of interlocking projections and recesses. The interlocking projections and recesses can be arranged on the first and second compressor housings and the at least one first and second rotating compressor element.

[0082] The at least one first compressor unit may comprise a radial compressor and / or an axial compressor. In particular, the at least one first compressor unit may comprise a radial compressor and an axial compressor.

[0083] The at least one first compressor unit and / or the second compressor unit each comprise a radial compressor and / or axial compressor

[0084] The radial compressor can be constructed in such a way that the first compressed fluid can flow axially, ie in the direction of the central axis of the first compressor unit, into the first compressor housing.

[0085] By means of the at least one first rotating compressor element, this fluid can then be radially deflected and pre-compressed and subsequently flow into an annular channel, the so-called volute, arranged radially outside the at least one first rotating compressor element.

[0086] Within the volute, a further pressure increase can occur due to the centrifugal and centripetal forces acting on the fluid and the design of the volute as an annular diffuser.

[0087] A flow channel formed by two adjacent blades (in particular its cross section) in the at least one first rotating compressor element can also expand in the flow direction (i.e. like the volute) in the sense of a diffuser.

[0088] The axial compressor, which can be configured as an inducer or worm gear, can be arranged upstream of the radial compressor. The axial compressor and the radial compressor can, in particular, be connected to each other in a rotationally fixed manner. The shroud can extend from the axial compressor to the radial compressor, thus comprising a common shroud for both compressors.

[0089] It can further be provided that the drive unit has an electric motor. This electric motor can comprise a stator, which can be arranged on or in the drive unit housing. The rotating drive element can thus form a rotor of the electric motor, wherein, in the assembled state, an annular gap is formed between the rotor and stator. The annular gap can, in particular, be designed as a transmission gap between the rotor and stator. Furthermore, it can be provided that the annular gap is connected to the high-pressure region of the first and / or second compressor housing.

[0090] Additionally or alternatively, the drive unit may comprise a turbine unit. In this case, the drive unit housing may be configured as a turbine housing, and the rotating drive element as a turbine wheel. The turbine housing may have a fixed guide wheel arranged upstream of the turbine wheel. The turbine unit may be configured as an axial turbine or a radial turbine.

[0091] The compressor device may additionally or alternatively comprise one or more sealing gas channels, by means of which sealing gas can be guided from a sealing gas connection to a housing connection area between the drive unit housing and the first compressor housing.

[0092] Additionally or alternatively, the compressor device may comprise one or more sealing gas channels, by means of which sealing gas can be guided from a sealing gas connection to a housing connection area between the drive unit housing and the second compressor housing.

[0093] The barrier gas channel or channels can be particularly advantageous if the first compressed fluid and the second compressed fluid are different and mixing should be avoided.

[0094] Due to its design-related leakage flow, a labyrinth seal may no longer be sufficient as a sole seal, as described above. Therefore, at least one sealing gas channel can extend to each housing-side part of the first and second labyrinth seal, so that a leakage flow into the first or second compressor housing can be prevented.

[0095] It can be provided that the drive unit is arranged in the assembled state between the at least one first compressor unit and the second compressor unit.

[0096] The at least one first compressor unit and the second compressor unit can preferably be arranged along the central axis of the compressor device on opposite sides of the drive unit. Optionally, the at least one first compressor unit and the second compressor unit can thus form a mirror-symmetrical structure with respect to a central plane oriented perpendicular to the central axis of the compressor device.

[0097] The at least one first compressor unit may comprise a first inlet for sucking in the at least one first compressed fluid and the second compressor unit may comprise a second inlet for sucking in the second compressed fluid.

[0098] The first inlet can be arranged offset by 180° to the second inlet, so that the at least one first compressed fluid and the second compressed fluid can be introduced into the compressor device in opposite directions, in particular aligned facing each other.

[0099] However, the first inlet and the second inlet can also be offset at angles other than 180°. The center axes of the first and second inlets can be arranged at an included angle of preferably 90° to 180° to each other.

[0100] Additionally or alternatively, it can be provided that the at least one first rotating compressor element has a maximum outer diameter that is greater than a maximum outer diameter of the second rotating compressor element.

[0101] Due to the rotationally fixed coupling of the at least one first rotating compressor element and the second rotating compressor element, both compressor elements can only be operated at the same speed.

[0102] However, since the density of the first compressed fluid and the second compressed fluid can differ from each other for different fluids (for example, liquid oxygen has approximately four times the density of liquid methane), at least one of the two compressors cannot be operated in the optimal efficiency range.

[0103] A remedy for this can therefore be the adjustment of the maximum

[0104] However, this adjustment cannot be limited to the maximum

[0105] The outer diameter may be limited. Additionally or alternatively, the mean diameter and / or the inlet diameter of both compressor elements can be adjusted accordingly.

[0106] Alternatively, it can be provided that the at least one first rotating compressor element has a maximum outer diameter which is the same size as a maximum outer diameter of the second rotating compressor element.

[0107] Due to the rotationally fixed coupling of the at least one first rotating compressor element and the second rotating compressor element, both compressor elements can only be operated at the same speed.

[0108] However, since the density of the fluids is the same, both compressors can be operated at a certain speed in the optimal efficiency range and have the same outer diameter.

[0109] However, not only the maximum outer diameter can be the same. Additionally or alternatively, the mean diameter and / or the inlet diameter of both compressor elements can also be the same.

[0110] The at least one first rotating compressor element comprises more blades than the second rotating compressor element.

[0111] This embodiment can be considered in particular as a further measure for adapting the at least one first rotating compressor element to the first compressed fluid, which differs from the second fluid in particular in terms of density.

[0112] Alternatively, it can be provided that the at least one first rotating compressor element comprises the same number of blades as the second rotating compressor element.

[0113] This configuration can be considered, in particular, as a further measure for operating at least one first rotating compressor element and one second rotating compressor element with the same fluids. Alternatively, it can also be provided that the at least one first rotating compressor element comprises fewer blades than the second rotating compressor element.

[0114] It can also be provided that the plurality of blades of the at least one first rotating compressor element and the second rotating compressor element each differ from one another with respect to at least one geometric blade feature.

[0115] Such geometric airfoil features can include, in particular, an airfoil size, i.e., in particular, the airfoil height, the airfoil thickness, and the airfoil length. The airfoil height can be the height by which the airfoil protrudes from a compressor element hub. Further additional geometric airfoil features can include the airfoil surface, an airfoil pitch, or an airfoil curvature.

[0116] The at least one first compressed fluid and the second compressed fluid can be the same. The first or second compressed fluid can be selected from liquefied oxygen, liquefied hydrogen, liquefied methane, liquefied carbon dioxide, liquefied natural gas, liquefied propane, kerosene, ethanol, etc. The substances that are gaseous under normal conditions: oxygen, hydrogen, methane, carbon dioxide, natural gas and propane, are fed to the compressor device in a pre-compressed state, so that the first and second fluids in this case are to be understood as pre-compressed fluids (the pre-compression takes place outside the compressor device), whereas substances that are liquid under normal conditions, such as kerosene and ethanol, do not have to be fed to the compressor device in a pre-compressed state, since they are already in the liquid phase under normal conditions.

[0117] Alternatively, it can be provided that the at least one first compressed fluid and the second compressed fluid can be different. The first or second compressed fluid can therefore each be selected from liquefied oxygen, liquefied methane, liquefied carbon dioxide, liquefied natural gas, liquefied propane, kerosene, ethanol, etc. With liquefied hydrogen, due to its low density, it should be noted that it cannot be easily combined with other fluids in the compressor device described above (due to a large difference in density, due to the system). Furthermore, it can be provided that the first compressor bearing and / or second compressor bearing have / have a radial plain bearing surface and an axial plain bearing surface, by means of which an axial thrust compensation device is formed.

[0118] As explained above, when operating with different compressed fluids, the at least one first and second rotating compressor element can differ at least in terms of their outer diameter, resulting in different axial and radial forces. The resulting total axial force can also be referred to as axial thrust, which can be compensated by the first and / or second compressor bearings using the axial plain bearing surface and the corresponding housing axial bearing surface.

[0119] Additionally or alternatively, it can be provided that the third bearing has a radial plain bearing surface and an axial plain bearing surface, by means of which an axial thrust compensation device can be formed.

[0120] Further preferred features and / or advantages of the present invention are the subject of the following description and the drawings of exemplary embodiments.

[0121] The drawings show:

[0122] Fig. 1 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, from the prior art;

[0123] Fig. 2 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a first exemplary embodiment of the present invention;

[0124] Fig. 3 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a second exemplary embodiment of the present invention;

[0125] Fig. 4 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a third exemplary embodiment of the present invention;

[0126] Fig. 5 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a fourth exemplary embodiment of the present invention;

[0127] Fig. 6 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a fifth exemplary embodiment of the present invention;

[0128] Fig. 7 is a schematic sectional view of a compressor device for conveying compressed fluids, in particular liquefied propellants for rocket engines, according to a sixth exemplary embodiment of the present invention;

[0129] Fig. 8 is a diagrammatic comparison of the bearing concept of the compressor device according to Fig. 6 and the compressor device from the prior art according to Fig. 1; and

[0130] Fig. 9 is a diagrammatic comparison of the bearing concept of the compressor device according to Figs. 3 to 5 and 7 and the compressor device from the prior art according to Fig. 1.

[0131] Identical or functionally equivalent elements are provided with the same reference numerals in all figures.

[0132] Fig. 1 shows a schematic sectional view of a compressor device 100 for conveying compressed fluids from the prior art. The compressed fluids are preferably liquefied, i.e., pre-compressed, propellants for rocket engines.

[0133] Examples include cryogenic fluids such as liquefied oxygen, liquefied

[0134] Hydrogen, liquefied methane, liquefied carbon dioxide, liquefied natural gas, or liquefied propane are examples. However, non-cryogenic fuels such as kerosene or ethanol, etc., can also be extracted.

[0135] In the present case according to Fig. 1, it is a compressor device 100 for conveying compressed liquid hydrogen.

[0136] The compressor device 100 comprises a first compressor unit 102a and a second compressor unit 102b as well as a drive unit 110 for driving the first and second compressor units 102a, 102b.

[0137] Both the first and the second compressor unit 102a, 102b are designed as radial compressors 160 and have a first and a second compressor housing 104, 118.

[0138] According to Fig. 1, the first rotating compressor element 106 is mounted in the first compressor housing 104 by means of a shaft W and a first compressor bearing 108.

[0139] A second rotating compressor element 120 is axially (i.e. in the direction of the central axis M) pushed onto the first rotating compressor element 106 in a rotationally fixed manner.

[0140] The second rotating compressor element 120 is therefore arranged to rotate in the second compressor housing 118, but is not separately mounted therein.

[0141] The first and second compressor units 102a, 102b form a common two-stage compressor unit according to Fig. 1.

[0142] The drive unit 110 has a drive unit housing 112 in which a rotating drive element 114 is rotatably mounted by means of the shaft W and a drive bearing 116. According to Fig. 1, the drive unit 110 is designed in the form of a turbine unit 166, wherein the rotating drive element 114 is in turn formed by two series-connected axial turbine wheels 194.

[0143] The first and second rotating compressor elements 106, 120 are connected to the shaft W and to the rotating drive element 114 in the form of the two axial turbine wheels 194. The rotating drive element 114 is also connected to the shaft W.

[0144] The functionality of the compressor device 100 from the prior art is as follows:

[0145] Pressurized hot gas (e.g. from an external hot gas generator) flows on the side of the drive unit 110 from the turbine unit inlet 192 into the turbine volute 196, the cross section of which is designed as a nozzle, which leads to an acceleration of the hot gas.

[0146] The accelerated hot gas exits the turbine volute 196 via a substantially axially aligned connecting channel, resulting in an axial flow to both series-connected axial turbine wheels 194. The expanded hot gas then flows out of the turbine unit 166 via the turbine outlet 198.

[0147] In both turbine wheels 194, the hot gas is expanded and its kinetic energy is converted into rotational energy of the turbine wheels 194.

[0148] This rotational energy is transferred from the turbine wheels 194 via the rotationally fixed connection to the first and second rotating compressor elements 106, 120.

[0149] The first and second rotating compressor elements 106, 120 create a negative pressure at the first inlet, so that the liquid hydrogen can initially be introduced axially via this first inlet 176 into the two-stage compressor unit 102a, 102b.

[0150] The liquid hydrogen is initially compressed to a first pressure level by the first rotating compressor element (configured as a radial compressor element) 106 and introduced into a meandering flow channel. The liquid hydrogen flows through this flow channel into the second compressor unit 102b, where it is compressed to a second, higher pressure level by the second rotating compressor element 120 (also configured as a radial compressor element) into the compressor volute 200.

[0151] After flowing through the compressor volute 200, the liquefied and further compressed hydrogen flows out of the second compressor unit 102b through a compressor outlet 202 and can be fed to the rocket engine, for example, via a line.

[0152] Fig. 2 shows a schematic sectional view of a compressor device 100 for conveying compressed fluids according to a first exemplary embodiment of the present invention.

[0153] The compressed fluids are preferably liquefied, i.e., pre-compressed, propellants for rocket engines. These propellants are therefore already under a certain pressure (e.g., two- or three-digit pressure values ​​in bar) before entering the compressor unit.

[0154] Examples include cryogenic fluids such as liquefied oxygen, liquefied hydrogen, liquefied methane, liquefied carbon dioxide, liquefied natural gas, or liquefied propane. However, non-cryogenic fuels such as kerosene or ethanol, etc., can also be extracted.

[0155] The compressor device 100 shown in Fig. 2 can be used in particular for compressing or conveying compressed methane.

[0156] Compressor device 100 comprises a first compressor unit 102a for conveying a first compressed fluid F1 and a second compressor unit 102b for conveying a second compressed fluid F2.

[0157] The compressor device 100 further comprises a drive unit 110 for driving the first and second compressor units 102a, 102b. As can be seen in Fig. 2, the drive unit 110 is arranged in the assembled state between the first compressor unit 102a and the second compressor unit 102b.

[0158] The first compressor unit 102a and the second compressor unit 102b are arranged along the central axis M of the compressor device 100 on opposite sides of the drive unit 110.

[0159] Optionally, the first compressor unit 102a and the second compressor unit 102b form a mirror-symmetrical structure with respect to a central plane oriented perpendicular to the central axis M of the compressor device 100.

[0160] As mentioned above, the first compressed fluid F1 may be compressed methane.

[0161] The second compressed fluid F2 may also be compressed methane, so that the first fluid F1 and the second fluid F2 may be the same.

[0162] However, the first and second compressed fluids F1, F2 may also be fluids other than compressed methane, in particular different fluids.

[0163] However, the first and second compressed fluids F1, F2 can also be different fluids.

[0164] According to Fig. 2, the first compressor unit 102a has a radial compressor 160 and an axial compressor 162.

[0165] The first compressor unit 102a comprises a first compressor housing 104, which serves as a common housing for the radial compressor 160 and an axial compressor 162.

[0166] The first compressor housing 104 includes a first inlet 176 for sucking in the first compressed fluid F1.

[0167] The first compressor housing 104 has a cover-like base body 204, from which a hollow cylindrical housing section 206 protrudes on the inlet side and defines the inlet 176 at the end. The first compressor housing 104 has a central circular bore that is bounded radially (a direction perpendicular to the central axis M) and axially (a direction along the central axis M) by the hollow cylindrical housing section 206 and the base body 204.

[0168] This housing section 206 and the base body 204 form a housing section for the axial compressor 162 in the assembled state.

[0169] Within the axial extent of the cover-like base body 204, the circular bore extends directly into a truncated cone-shaped bore 208, the diameter of which increases towards the end facing away from the inlet.

[0170] The truncated cone-shaped bore 208 within the base body 204 forms a housing section for the radial compressor 160 in the assembled state.

[0171] Radially outside the frustoconical bore 208, a compressor volute 210 is introduced into the base body 204, wherein an outlet is arranged on the volute 210 (not shown in Fig. 2) through which the compressed first fluid can flow out of the compressor volute.

[0172] The central circular bore, the frustoconical bore or recess 208 and the compressor volute 210 provide a flow path for the first compressed fluid from the first inlet 176 to the outlet.

[0173] The first compressor unit 102a also includes a first rotating compressor element 106.

[0174] The first rotating compressor element 106 is rotatably mounted in the first compressor housing 104 by means of a first compressor bearing 108.

[0175] The first rotating compressor element 106 is mounted directly in the first compressor housing 104.

[0176] According to Fig. 2, a direct bearing arrangement can be understood in particular to mean that the bearing arrangement of the first rotating compressor element 106 is achieved without a drive shaft and without a compressor shaft. The first rotating compressor element 106 has an inducer (also called a worm gear) and a compressor wheel, wherein the inducer is arranged upstream of the compressor wheel in the assembled state.

[0177] The inducer, together with the housing section 206 and the base body 204 of the first compressor housing 104, forms the axial compressor 162.

[0178] Accordingly, the compressor wheel together with the truncated cone-shaped bore 208 within the base body 204 forms the radial compressor 160.

[0179] The first compressor bearing 108 is arranged on a radially outer surface 132 of the first rotating compressor element 106.

[0180] On the housing side, the first compressor bearing 108 is accommodated at least in the housing section 206 by a corresponding bearing surface.

[0181] According to Fig. 2, the first compressor bearing 108 comprises two ceramic fiber composite material plain bearings 138 (hereinafter also: CMC plain bearings), wherein the plain bearing 138 designed as a radial bearing is accommodated in the housing section 206.

[0182] The CMC plain bearings can be designed as plain bearing sleeves and can have a fiber-reinforced porous ceramic structure. The fibers can preferably be carbon fibers, although other suitable fiber materials can also be used.

[0183] Thanks to the porous ceramic structure, the CMC plain bearings can store a certain amount of lubricant and release it back to the surrounding housing or compressor element parts in the form of transpiration lubrication.

[0184] The CMC plain bearings can have or be selected from the following material pairings (fiber material / ceramic structure or matrix structure): C / SiCN, C / SiCO, C / CSiC and / or C / C.

[0185] Oxipol can also be designed as a ceramic structure or matrix structure, for example, with carbon (C) as the fiber material. Oxipol is a so-called O-CMC (oxide fiber composite material), which is oxidation-resistant and thus also suitable for use in oxygen-based oxidizing environments.

[0186] During the manufacturing process of the porous CMC material, an adjustable permeability for the flow through the composite of fiber material / matrix structure can be imposed by controlling the material porosity. The permeability, which can be discretely measured in all orthotropic directions on corresponding laboratory samples, can be quantified using permeability coefficients kd and kf (Darcy-Forchheimer coefficients).

[0187] The plain bearing 138, designed as a combined axial and radial bearing, is accommodated in the truncated conical bore 208 by means of a further housing bearing surface.

[0188] According to Fig. 2, the first rotating compressor element 106 comprises a plurality of blades 140a, the outer ends of which are connected by a first closed casing 142, the outer surface of which forms the casing surface 132.

[0189] The casing 142 has on its casing surface two bearing areas or surfaces for the two plain bearings 138 of the first compressor bearing 108.

[0190] The first compressor housing 104 has a first return channel 146 which extends from a high pressure region 148 of the first compressor housing 104 to the first compressor bearing 108.

[0191] The high pressure region 148 can be regarded in particular as that radial region of the compressor wheel or the first compressor housing which has exceeded a certain limit pressure compared to the inlet pressure upstream of the first rotating compressor element.

[0192] The return channel 146 extends from the truncated cone-shaped bore 208 of the base body 204, in which a significant pressure increase is already achieved, to the plain bearing 138 designed as a radial bearing.

[0193] Alternatively, the return channel can also extend from the compressor volute 200 or open into it. A further return channel branches off from the return channel 146, which extends to the further plain bearing 138, which is designed as a combined axial and radial bearing.

[0194] Accordingly, a partial mass flow of the at least one first compressed first fluid F1 can be supplied to the first compressor bearing 108 for its lubrication and cooling.

[0195] After flowing through the radial plain bearing 138 and the combined axial and radial bearing 138, the first fluid F1 can, for example, flow back to the first inlet 176 and be fed again to the first rotating compressor element 106.

[0196] The first compressor housing 104 further comprises a first labyrinth seal 156 for its sealing, which is arranged between the first compressor housing 104 and the first rotating compressor element 106.

[0197] The labyrinth seal 156 is arranged in the frusto-conical bore 208 of the first compressor housing 104.

[0198] The labyrinth seal 156 is formed by correspondingly interlocking projections and recesses of the frustoconical bore 208 of the first compressor housing 104 and the casing 142.

[0199] The first labyrinth seal 156 has a leakage mass flow of the first compressed fluid F1, which can be fed to the first return channel 146,

[0200] Furthermore, the drive unit 110 comprises a drive unit housing 112.

[0201] The first compressor housing 104 and the drive unit housing 112 have a housing connection area 172 in the assembled state.

[0202] According to Fig. 2, the housing connection area 172 is designed as a positive connection area with a housing shoulder and housing recess provided in the first compressor housing 104, into which a corresponding projection and shoulder of the drive unit housing 112 can engage. In the housing connection area 172, the first compressor housing 104 and the drive unit housing 112 are connected to one another via detachable fastening elements such as screws.

[0203] According to Fig. 2, the second compressor unit 102b also has a radial compressor 160 and an axial compressor 162.

[0204] In particular, the second compressor unit 102b is constructed in the same way as the first compressor unit 102a, so that the above explanations regarding the first compressor unit 102 can be transferred correspondingly to the second compressor unit.

[0205] The second compressor unit 102b comprises a second compressor housing 118, which serves as a common housing for the radial compressor 160 and an axial compressor 162.

[0206] The second compressor housing 118 includes a second inlet 178 for sucking in the second compressed fluid F2.

[0207] The second compressor housing 118 has a cover-like base body 204, from which a hollow cylindrical housing section 206 rises on the inlet side and defines the second inlet 178 at the end.

[0208] The second compressor housing 118 has a central or central circular bore which is bounded radially (a direction perpendicular to the central axis M) and axially (a direction along or along the central axis M) by the hollow cylindrical housing section 206 and the base body 204.

[0209] This housing section 206 and the base body 204 form a housing section for the axial compressor 162 in the assembled state.

[0210] Within the axial extension of the cover-like base body 204, the circular bore merges directly into a truncated cone-shaped bore 208, the diameter of which increases towards the end of the base body facing away from the inlet.

[0211] The frustoconical bore 208 within the base body 204 forms, in the assembled state, a housing section for the radial compressor 160. Radially outside the frustoconical bore 208, a compressor volute 210 is introduced into the base body 204, wherein an outlet is arranged on the compressor volute 210 (not shown in Fig. 2), via which the compressed second fluid F2 can flow out of the compressor volute 210.

[0212] The central circular bore, the frustoconical bore or recess 208 and the compressor volute 210 provide a flow path for the second compressed fluid F2 from the second inlet 178 to the outlet.

[0213] The second compressor unit 102b also includes a second rotating compressor element 120.

[0214] The second rotating compressor element 120 is rotatably mounted in the second compressor housing 118 by means of a second compressor bearing 122.

[0215] The second rotating compressor element 120 is mounted directly in the second compressor housing 118.

[0216] According to Fig. 2, a direct bearing can be understood in particular in such a way that the bearing of the second rotating compressor element 120 is accordingly accomplished without a drive shaft and without a compressor shaft.

[0217] The second rotating compressor element 120 has an inducer (also called a worm wheel) and a compressor wheel, wherein the inducer is arranged upstream of the compressor wheel in the assembled state.

[0218] The inducer, together with the housing section 206 and the base body 204 of the second compressor housing 118, forms the axial compressor 162.

[0219] Accordingly, the compressor wheel together with the truncated cone-shaped bore 208 within the base body 204 forms the radial compressor 160.

[0220] The second compressor bearing 122 is arranged on a radially outer surface 136 of the second rotating compressor element 120. On the housing side, the second compressor bearing 122 is accommodated at least in the housing section 206 by a corresponding bearing surface.

[0221] According to Fig. 2, the second compressor bearing 122 comprises two ceramic fiber composite material plain bearings 138 (hereinafter also: CMC plain bearings), wherein the plain bearing 138 designed as a radial bearing is accommodated in the housing section 206.

[0222] The CMC plain bearings can be designed as plain bearing sleeves and can have a fiber-reinforced porous ceramic structure. The fibers can preferably be carbon fibers, although other suitable fiber materials can also be used.

[0223] Thanks to the porous ceramic structure, the CMC plain bearings can store a certain amount of lubricant or fluid F2 and release it back to the surrounding housing or compressor element parts in the form of transpiration lubrication.

[0224] As described above, during the manufacturing process of the porous CMC material, an adjustable permeability for the flow through the composite of fiber material / matrix structure can be imposed by influencing the material porosity. The permeability, which can be discretely measured in all orthotropic directions on corresponding laboratory samples, can be quantified using permeability coefficients kd and kf (Darcy-Forchheimer coefficients).

[0225] The plain bearing 138, designed as a combined axial and radial bearing, is accommodated in the truncated conical bore 208 by means of a further housing bearing surface.

[0226] Thus, the first compressor bearing 108 and / or the second compressor bearing 122 can have a radial plain bearing surface 180 and an axial plain bearing surface 182, through which an axial thrust compensation device 184 is formed.

[0227] According to Fig. 2, the second rotating compressor element 120 comprises a plurality of blades 140b, the outer ends of which are connected by a second closed casing 144, the outer surface of which forms the casing surface 132.

[0228] The second closed casing 144 has two bearing areas or surfaces on its casing surface for the two plain bearings 138 of the second compressor bearing 122. The second compressor housing 118 has a second return channel 154 that extends from a high-pressure region 152 of the second compressor housing 118 to the second compressor bearing 122.

[0229] The high-pressure region 152 can be regarded in particular as that radial region of the compressor wheel or the second compressor housing 118 which has exceeded a certain limit pressure compared to the inlet pressure upstream of the second rotating compressor element 120.

[0230] The second return channel 154 extends from the truncated cone-shaped bore 208 of the base body 204, in which a significant pressure increase is already achieved, to the plain bearing 138 designed as a radial bearing.

[0231] Alternatively, the return channel 154 can also extend from the compressor volute 200 or open into it.

[0232] A further return channel is also branched off from the second return channel 154, which extends to the further plain bearing 138 designed as a combined axial and radial bearing.

[0233] Accordingly, a partial mass flow of the at least one first compressed fluid F1 can be supplied to the second compressor bearing 122 for its lubrication and cooling.

[0234] After flowing through the radial plain bearing 138 and the combined axial and radial bearing 138, the second fluid F2 can, for example, flow back to the second inlet 178 and be fed again to the second rotating compressor element 120.

[0235] The first inlet 176 is offset by 180° from the second inlet 178, so that the at least one first compressed fluid F1 and the second compressed fluid F2 can be introduced into the compressor device 100 in opposite directions, in particular facing each other. The second compressor housing 118 further comprises a second labyrinth seal 158 for sealing purposes, which is arranged between the second compressor housing 118 and the second rotating compressor element 120.

[0236] The second labyrinth seal 158 is arranged in the frustoconical bore 208 of the second compressor housing 118.

[0237] The second labyrinth seal 158 is formed by correspondingly interlocking projections and recesses of the frustoconical bore 208 of the first compressor housing 104 and the second casing 144.

[0238] The second labyrinth seal 158 further comprises a leakage mass flow of the second compressed fluid F1, which can be fed to the second return channel 154,

[0239] The second compressor housing 118 and the drive unit housing 112 have a housing connection area 174 in the assembled state.

[0240] According to Fig. 2, the housing connection area 174 is designed as a positive connection area with a housing shoulder and housing recess provided in the second compressor housing 118, into which a corresponding projection and shoulder of the drive unit housing 112 can engage.

[0241] In the housing connection area 174, the second compressor housing 118 and the drive unit housing 112 are connected to each other via detachable fastening elements such as screws.

[0242] The drive unit housing 112 is designed in two parts according to Fig. 2, wherein both housing halves are also fastened to one another by means of a positive connection area and detachable fastening elements as described above in connection with the first and second connection areas 172, 174.

[0243] The drive unit housing 112 comprises a rotating drive element 114, wherein the rotating drive element 114 is rotatably mounted in the drive unit housing 112 by means of a drive bearing 116. The rotating drive element 114 is, in particular, mounted directly in the drive unit housing 112.

[0244] Consequently, a drive shaft and / or compressor shaft can also be dispensed with with regard to the drive bearing 116, which is exposed to increased bending loads with regard to Fig. 1.

[0245] The drive bearing 116 is arranged on a radially outer surface 134 of the rotating drive element 114.

[0246] The drive bearing 116 comprises two ceramic fiber composite plain bearings 138.

[0247] Both plain bearings 138 are each accommodated at the end in the drive unit housing 112 by respective housing recesses.

[0248] The rotating drive element 114 has two radial projections in the axial region of these two housing recesses, which have the respective drive element bearing surface for the two plain bearings at their radial ends.

[0249] The drive unit 110 has an electric motor 164 as shown in Fig. 2.

[0250] The electric motor 164 includes a stator 186 disposed on or in the drive unit housing 112.

[0251] Furthermore, rotating drive element 114 forms a rotor 188 of the electric motor 164.

[0252] In the assembled state, an annular gap 190 (also called transmission gap) is formed between rotor 188 and stator 186.

[0253] The compressor device 100 comprises two sealing gas channels 168 within the drive unit housing 112.

[0254] By means of these sealing gas channels 168, sealing gas can be guided from a sealing gas connection 170 to a housing connection area 172, 174 between the drive unit housing 112 and the first compressor housing 104 and the second compressor housing 118. The sealing gas channels 168 each extend to the ceramic fiber composite plain bearings 138, where they enable effective sealing against the high-pressure area of ​​the first and second compressor housings 104, 118 and the housing connection areas 172, 174.

[0255] Consequently, the drive bearing 116 may additionally have a radial plain bearing surface 180 and an axial plain bearing surface 182, through which an axial thrust compensation device 184 is formed.

[0256] In this respect, the annular gap 190 is filled only with the sealing gas, which can be helium, for example, although other suitable gases can also be used.

[0257] According to Fig. 2, the rotating drive element 114, the first rotating compressor element 106 and the second rotating compressor element 120 are connected to one another in a rotationally fixed manner in the assembled state.

[0258] The rotating drive element 114, the first rotating compressor element 106 and the second rotating compressor element 120 have a central cavity 124, 126, 128 extending axially along the central axis M of the compressor device 100.

[0259] As shown in Fig. 2, the rotating drive element 114, the first rotating compressor element 106 and the second rotating compressor element 120 form a common cavity 130.

[0260] The central cavity 124 of the rotating drive element 114, the central cavity 126 of the first rotating compressor element 106, and the central cavity 128 of the second rotating compressor element 120 are to be understood as containing no machine elements, bearings, sealing elements, or other components. The same applies to the common cavity 130.

[0261] The cavity 124 of the rotating drive element 114 has a larger cross-sectional area oriented perpendicular to the central axis M of the compressor device 100 than the cavity 126, 128 of the first rotating compressor element 106 and second rotating compressor element 120. Fig. 3 shows a schematic sectional view of a compressor device 100 for conveying compressed fluids according to a second exemplary embodiment of the present invention.

[0262] The compressor device 100 is in the present case the compressor device 100 described in connection with Fig. 2, wherein the sealing gas channels and the drive bearing by means of the ceramic fiber composite material plain bearings are not provided.

[0263] The compressor device 100 shown in Fig. 3 can be used in particular for compressing or conveying compressed oxygen, so that the first and second fluid are each compressed oxygen.

[0264] In addition, the annular gap 190 is connected to the high-pressure region 148, 152 of the first and second compressor housings 104, 118 via a respective connecting channel.

[0265] Fig. 4 shows a schematic sectional view of a compressor device 100 for conveying compressed fluids according to a third exemplary embodiment of the present invention.

[0266] The compressor device 100 is in the present case the compressor device 100 described in connection with Fig. 2, wherein the sealing gas channels and the drive bearing by means of the ceramic fiber composite material plain bearings are not provided.

[0267] The compressor device 100 shown in Fig. 4 can be used in particular for compressing or conveying compressed methane, so that the first and second fluid is each compressed methane.

[0268] In addition, the annular gap 190 is connected to the high-pressure region 148, 152 of the first and second compressor housings 104, 118 via a respective connecting channel.

[0269] Fig. 5 shows a schematic sectional view of a compressor device for conveying compressed fluids, according to a fourth exemplary embodiment of the present invention.

[0270] The compressor device 100 is the one described in connection with Fig. 2

[0271] Compressor device 100, wherein the drive bearing is not provided. Furthermore, the drive unit 110 is not designed as an electric motor. Rather, the drive unit has a turbine unit 166.

[0272] The rotating drive element 114 is formed by an axial turbine wheel 194. For this purpose, pressurized hot gas (e.g., from an external hot gas generator) is supplied to a turbine unit inlet (not shown in Fig. 5), from where it flows through the housing-mounted guide wheel and axially downstream of the turbine wheel. The expanded hot gas then flows out of the turbine unit 166 via the turbine outlet (not shown in Fig. 5).

[0273] In the turbine wheel 194, the hot gas is expanded and its kinetic energy is converted into rotational energy of the turbine wheel 194.

[0274] This rotational energy is transferred from the turbine wheel 194 via the rotationally fixed connection to the first and second rotating compressor elements 106, 120, so that the necessary compression work is provided.

[0275] The compressor device 100 shown in Fig. 5 can be used in the first compressor unit 102a for compressing or conveying compressed oxygen.

[0276] On the other hand, the second compressor unit 102b can be used to compress or convey compressed methane, so that the first fluid F1 and second fluid F2 are each different.

[0277] Accordingly, the first rotating compressor element 106 has a maximum outer diameter that is smaller than a maximum outer diameter of the second rotating compressor element 120.

[0278] The differences in diameter take into account in particular the different densities of the compressed oxygen and the compressed methane.

[0279] In addition, it may be conceivable that the first rotating compressor element 106 comprises fewer blades 140a than the second rotating compressor element 120.

[0280] The plurality of blades 140a, 140b of the first rotating compressor element 106 and the second rotating compressor element 120 may each differ from one another with respect to at least one geometric blade feature, in particular with respect to size, area and / or pitch.

[0281] Such geometric airfoil features can include, for example, an airfoil size, in particular the airfoil height, the airfoil thickness, and the airfoil length. The airfoil height can be the height by which the airfoil protrudes from a compressor element hub. Further additional geometric airfoil features can be the airfoil surface, an airfoil pitch, or an airfoil curvature.

[0282] Fig. 6 shows a schematic sectional view of a compressor device for conveying compressed fluids according to a fifth exemplary embodiment of the present invention.

[0283] The compressor device 100 is the compressor device 100 described in connection with Fig. 4, wherein rolling bearings are used instead of plain bearings.

[0284] Fig. 7 shows a schematic sectional view of a compressor device for conveying compressed fluids according to a sixth exemplary embodiment of the present invention;

[0285] The compressor device 100 is in the present case the compressor device 100 described in connection with Fig. 4, wherein the compressor device 100 described in Fig. 7 does not have two plain bearings per first and second compressor bearing 108, 122.

[0286] Fig. 8 shows a diagrammatic comparison of the bearing concept of the compressor devices according to Fig. 6 and the compressor device from the prior art according to Fig. 1; and

[0287] The schematic diagram shows the large bearing distance, which leads to a deflection of the shaft in the state of the art.

[0288] This problem can be addressed with the compressor device 100 according to the present invention because it offers the greatest possible section modulus in the critical range of maximum shaft deflection. In this respect, the compressor device 100 can promise a simpler design, lower manufacturing costs, greater operational reliability, reduced maintenance requirements, and / or an increased service life, thus enabling reusability.

[0289] Fig. 9 is a diagrammatic comparison of the bearing concept of the compressor device according to Figs. 2 to 5 and 7 and the compressor device from the prior art according to Fig. 1.

[0290] The bearing of the compressor device 100 shown in principle in Fig. 9 is in the present case the bearing of the compressor device 100 described in connection with Fig. 8, wherein the illustrations of Fig. 8 and Fig. 9 differ only in the basic design of the first and second compressor bearings 108, 122.

[0291] List of reference symbols

[0292] Compressor device a first compressor unit b second compressor unit first compressor housing first rotating compressor element first compressor bearing

[0293] drive unit

[0294] Drive unit housing rotating drive element

[0295] Drive bearing second compressor housing second rotating compressor element second compressor bearing central cavity central cavity central cavity common cavity radially outer surface of the first rotating compressor element radially outer surface of the rotating drive element radially outer surface of the second rotating

[0296] Compressor element ceramic fiber composite plain bearings a blades b blades first closed casing second closed casing first return channel

[0297] High pressure area of ​​the first compressor housing one or more return channels of the drive unit housing

[0298] High pressure area of ​​the second compressor housing second return channel first labyrinth seal second labyrinth seal 160 centrifugal compressor

[0299] 162 axial compressors

[0300] 164 electric motor

[0301] 166 Turbine unit

[0302] 168 Sealing gas channel

[0303] 170 Seal gas connection

[0304] 172 Housing connection area between drive unit housing and first compressor housing

[0305] 174 Housing connection area between drive unit housing and second compressor housing

[0306] 176 first entry

[0307] 178 second entrance

[0308] 180 radial plain bearing surface

[0309] 182 axial plain bearing surface

[0310] 184 Axial thrust compensation device

[0311] 186 Stator

[0312] 188 Rotor

[0313] 190 annular gap

[0314] 192 Turbine inlet

[0315] 194 axial turbine

[0316] 196 Volute of the turbine

[0317] 198 Turbine outlet

[0318] 200 compressor volute

[0319] 202 Compressor outlet

[0320] 204 basic bodies

[0321] 206 Housing section

[0322] 208 conical bore

[0323] 210 Compressor Volute

[0324] F1 first compressed fluid

[0325] F2 second compressed fluid

[0326] M central axis

[0327] W wave

Claims

Patent claims 1. Compressor device (100) for conveying compressed fluids, in particular liquefied propellants for rocket engines, comprising: - at least one first compressor unit (102a) for conveying at least one first compressed fluid (F1), which comprises a first compressor housing (104) and at least one first rotating compressor element (106), wherein the at least one first rotating compressor element (106) is rotatably mounted in the first compressor housing (104) by means of a first compressor bearing (108); and - a drive unit (110) for driving the at least one first compressor unit (102a), wherein the drive unit (110) comprises a drive unit housing (112) and a rotating drive element (114), wherein the rotating drive element (114) is rotatably mounted in the drive unit housing (112) by means of a drive bearing (116).

2. Compressor device (100) according to claim 1, characterized in that the rotating drive element (114) and the at least one first rotating compressor element (106) are connected to one another in a rotationally fixed manner in the assembled state.

3. Compressor device (100) according to claim 1 or claim 2, characterized in that the compressor device (100) comprises a second compressor unit (102b) for conveying a second compressed fluid (F2), which comprises a second compressor housing (118) and a second rotating compressor element (120), wherein the second rotating compressor element (120) is rotatably mounted in the second compressor housing (118) by means of a second compressor bearing (122) and wherein the rotating drive element (114) and the second rotating compressor element (120) are connected to one another in a rotationally fixed manner in the assembled state.

4. Compressor device (100) according to one of the preceding claims, characterized in that the rotating drive element (114) and / or the at least one first rotating compressor element (106) and / or the second rotating compressor element (120) have / has a central cavity (124, 126, 128) extending axially along the central axis (M) of the compressor device (100), and / or wherein the rotating drive element (114), the at least one first rotating compressor element (106) and the second rotating compressor element (120) have a common cavity (130).

5. Compressor device (100) according to claim 4, characterized in that the cavity (124) of the rotating drive element (114) has a larger cross-sectional area oriented perpendicular to the central axis (M) of the compressor device (100) than the cavity (126, 128) of the at least one first rotating compressor element (106) and / or the second rotating compressor element (120), and / or wherein the rotating drive element (114), the at least one first rotating compressor element (106) and / or the second rotating compressor element (120) are / is mounted directly, consequently in particular without a drive shaft and / or compressor shaft, in the first compressor housing (104), the drive unit housing (112) and / or the second compressor housing (118).

6. Compressor device (100) according to one of the preceding claims, characterized in that the first compressor bearing (108) is arranged on a radially outer surface (132) of the at least one first rotating compressor element (106), and / or wherein the drive bearing (116) is arranged on a radially outer surface (134) of the rotating drive element (114), and / or wherein the second compressor bearing (122) is arranged on a radially outer surface (136) of the second rotating compressor element (120), and / or wherein the first compressor bearing (108) and / or the second compressor bearing (122) and / or the drive bearing (116) comprise / comprise one or more ceramic fiber composite material plain bearings (138).

7. Compressor device (100) according to claim 6, characterized in that the at least one first rotating compressor element (106) comprises a plurality of blades (140a), the outer ends of which are connected by a first closed casing (142), the outer surface of which forms the lateral surface (132) which has at least one bearing region for the first compressor bearing (108), and / or wherein the second rotating compressor element (120) comprises a plurality of blades (140b), the outer ends of which are connected by a second closed casing (144), the outer surface of which forms the lateral surface (136) which has at least one bearing region for the second compressor bearing (122).

8. Compressor device (100) according to one of claims 3 to 7, characterized in that the first compressor housing (104) has a first return channel (146) which extends from a high-pressure region (148) of the first compressor housing (104) to the first compressor bearing (108), so that a partial mass flow of the at least one first compressed fluid (F1) can be supplied to the first compressor bearing (108) for its lubrication and / or cooling; and / or wherein the drive unit housing (112) has one or more return channels (150) which extend from a high-pressure region (148, 152) of the first compressor housing (104) and / or the second compressor housing (118) to the drive bearing (116), so that a partial mass flow of the at least one first compressed fluid (F1) and / or the second fluid (F2) can be supplied to the drive bearing (116) for its lubrication and / or cooling;and / or wherein the second compressor housing (118) has a second return channel (154) which extends from a high-pressure region (152) of the second compressor housing (118) to the second compressor bearing (122), so that a partial mass flow of the second compressed fluid (F2) can be supplied to the second compressor bearing (122) for its lubrication and / or cooling.; 9. Compressor device (100) according to claim 8, characterized in that the first compressor housing (104) comprises a first labyrinth seal (156) for sealing it, which is arranged between the first compressor housing (104) and the at least one first rotating compressor element (106) is arranged and which has a leakage mass flow of the at least one first compressed fluid (F1) which can be fed to the first return channel (146), and / or wherein the second compressor housing (118) comprises, for its sealing, a second labyrinth seal (158) which is arranged between the second compressor housing (118) and the second rotating compressor element (120) and which has a leakage mass flow of the second compressed fluid (F2) which can be fed to the second return channel (154).

10. Compressor device (100) according to one of the preceding claims, characterized in that the at least one first compressor unit (102a) and / or the second compressor unit (102b) each have / have a radial compressor (160) and / or axial compressor (162), and / or wherein the drive unit (110) has / have an electric motor (164) and / or a turbine unit (166), and / or wherein the compressor device (100) comprises one or more sealing gas channels (168), by means of which sealing gas can be guided from a sealing gas connection (170) to a housing connection area (172, 174) between the drive unit housing (112) and the first compressor housing (104) and / or the second compressor housing (118).

11. Compressor device (100) according to one of claims 3 to 10, characterized in that the drive unit (110) is arranged in the assembled state between the at least one first compressor unit (102a) and the second compressor unit (102b), wherein the at least one first compressor unit (102a) and the second compressor unit (102b) are arranged along the central axis (M) of the compressor device (100) on opposite sides of the drive unit (110) and thereby optionally form a mirror-symmetrical structure to a central plane oriented perpendicular to the central axis (M) of the compressor device (100).

12. Compressor device (100) according to claim 11, characterized in that the at least one first compressor unit (102a) comprises a first inlet (176) for sucking in the at least one first compressed fluid (F1) and that the second compressor unit (102b) comprises a second inlet (178) for sucking in the second compressed fluid (F2), wherein the first inlet (176) is arranged offset by 180° to the second inlet (178), so that the at least one first compressed fluid (F1) and the second compressed fluid (F2) can be introduced into the compressor device (100) in opposite directions, in particular aligned facing each other, and / or wherein the at least one first rotating compressor element (106) has a maximum outer diameter that is greater than, smaller than, or equal to a maximum outer diameter of the second rotating compressor element (120).

13. Compressor device (100) according to one of the preceding claims, characterized in that the at least one first rotating compressor element (106) comprises more or the same number of blades (140a, 140b) than / as the second rotating compressor element (120), wherein the plurality of blades (140a, 140b) of the at least one first rotating compressor element (106) and the second rotating compressor element (120) each differ from one another with regard to at least one geometric blade feature, in particular with regard to size, area and / or pitch.

14. Compressor device (100) according to one of claims 3 to 13, characterized in that the at least one first compressed fluid (F1) and the second compressed fluid (F2) are the same, wherein the first compressor bearing (108) and / or drive bearing (116) and / or second compressor bearing (122) have / have a radial plain bearing surface (180) and an axial plain bearing surface (182) by means of which an axial thrust compensation device (184) is formed.

15. Compressor device (100) according to one of claims 10 to 14, characterized in that the electric motor (164) comprises a stator (186) which is arranged on or in the drive unit housing (112) and in that the rotating drive element (114) forms a rotor (188) of the electric motor (164), wherein in the assembled state between the rotor (188) and the stator (186) an annular gap (190) which is connected to the high-pressure region (148, 152) of the first and / or second compressor housing (104, 118).

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