Ventilation device with a damping and sealing element between different housing parts

Abstract

The invention relates to a compressor (1) for conveying an air flow and / or a gas flow and to a breathing apparatus or an anaesthesia apparatus with such a compressor (1). The compressor (1) has a housing (2) in which a compressor wheel (6) is arranged in a rotatable manner and is connected to an electric motor (5) by means of a drive shaft (4), an air flow and / or a gas flow being conveyed from an inlet (9) arranged upstream on a suction side (7) of the compressor wheel (6) through a flow channel (11) to an outlet (9) arranged downstream on a pressure side (8) of the compressor wheel (6) when the compressor wheel is rotated. The invention is characterized in that the compressor wheel (6) arranged in the housing interior (3) is at least partially surrounded by the housing and by a cover element (12), the housing being designed as a collecting housing (2) for the air flow and / or the gas flow coming from the compressor wheel (6) and being arranged at least partially on the pressure side (9) of the compressor wheel (6), the cover element being arranged at least partially on the suction side (7) of the compressor wheel (6) and being separated from the compressor wheel (6) at least partially by a gap (13), wherein at least one decoupling element (15) is arranged between the cover element (12) and the collecting housing (2) and between a functional component (14) connected at least indirectly to the compressor wheel (6) and / or to the electric motor (5) and the collecting housing (2) respectively for damping and at least partial sealing of the housing interior (3) from the surroundings (16).

Description

TECHNICAL FIELD

[0001] The invention relates to a compressor for conveying an air flow and / or a gas flow, with a housing, in the housing interior of which a compressor wheel is arranged in a rotatable manner and is connected to an electric motor by means of a drive shaft. Upon rotation of the compressor wheel, the air flow and / or the gas flow is conveyed from an inlet arranged upstream on the suction side of the compressor wheel through a flow channel to an outlet arranged downstream on the pressure side of the compressor wheel. Compressors of this type are used, for example, in artificial respiration or anesthesia devices in order to supply a patient with a required breathing gas flow, respectively. BACKGROUND

[0002] The artificial respiration or anesthesia devices are often supplied with the required gas mixture by a central gas supply of a hospital to which the devices are connected. Ventilation devices with suitable compressors are, however, increasingly installed in artificial respiration and anesthesia devices, through which a breathing gas flow, which can have an air or otherwise composed gas mixture, is conveyed to a patient in the required state parameters. In this interrelationship, it is conceivable to convey the breathing gas flow at a continuous pressure level or to dynamically change the pressure level in order to achieve, for example, a targeted artificial respiration mode or artificial respiration action.

[0003] Important for ventilation devices used in artificial respiration or anesthesia devices is that such ventilation devices have a compact design, are able to generate a breathing gas flow with the required state parameters for a corresponding patient artificial respiration and emit as little sound as possible, which is usually in the form of solid-borne sound caused by vibrations of the motor part or the housing part. Since all three of the aforementioned design criteria cannot usually be fulfilled to the same extent, the development and design of such compressors is often based on an optimization in order to at least sufficiently fulfill each of the three design criteria.

[0004] In this interrelationship, a ventilation device with a rotary compressor for an artificial respiration system is known from US 5,875,783. Due to the special dimensioning and shaping and the properties achieved thereby, the compressor is particularly suitable for tracking pressure fluctuations that occur primarily when supporting a patient who breathes at least partially autonomously.

[0005] Another ventilation device for artificial respiration and anesthesia devices is known from DE 197 14 644 C2. The ventilation device has a radial compressor with backwardly curved vanes. Due to the special shaping of the compressor wheel, it is possible upon corresponding control of the electric motor to cover a large rotational speed and pressure range within only a time period of milliseconds.

[0006] Furthermore, WO 2007 / 134405 A1 describes a ventilation device, the outstanding feature of which should be a low sound emission. Important for the ventilation device is that the plurality of compressor stages are arranged in a row in terms of flow technology and all of the flow-guiding components are surrounded by an additional housing.

[0007] A further rotary compressor is known from DE 199 04 119 C2. The drive of the compressor is accomplished by means of an electronically commutated DC motor, the rotor of which is formed by a permanent magnet connected with the compressor wheel, wherein the rotor is separated from the stator of the DC motor by means of a gap pot sealing. Furthermore, the compressor wheel is supported by means of aerodynamic gas sliding bearings and is surrounded by a housing composed of a plurality of components. With the described technical solution, direct contact between the rotating parts of the electric motor and the housing should primarily be prevented.

[0008] Since the solution described in DE 199 04 119 C2 has a relatively costly construction, the known alternative solution provides an additional housing, the so-called secondary housing, which surrounds the compressor and the helical housing, also called primary housing, which adjoins this compressor and guides the air or gas flow.

[0009] In order to further minimize the sound emission when using a secondary housing, measures are usually taken to reduce the transmission of vibrations. In this interrelationship, it is known, for example, that the structural unit consisting of the motor, the compressor wheel and the primary housing is clamped in the secondary housing by means of a flexible, soft receptacle or decoupling element. In this case, sound insulation is achieved by means of the additional housing and the further insulation element, so that, although the noise load on the patient and the nursing staff is ultimately minimized, the realization of a compact compressor construction form is impeded for this purpose.

[0010] The problem of the compressors known from the prior art, in particular used in artificial respiration and anesthesia devices, is that, although their design is feasible in terms of the required power parameters, a compact construction form and a low sound emission are additionally important design criteria. The optimal fulfillment of all three design criteria as far as possible is often a great problem. SUMMARY

[0011] Starting from the compressors known from the prior art and the problems described above, the task of the present application is to specify a technical solution which makes it possible to provide a compressor which is optimized in terms of three important design criteria, namely power characteristics, construction form and sound emission. A compressor should thus be created which is suitable for use in artificial respiration and / or anesthesia apparatuses and which is characterized by a compact construction form, suitable power characteristics and low sound emission. It is important here to minimize the load on the patient and the nursing staff caused by sound emissions from the compressor, for example by vibrations of different components.

[0012] In terms of pneumatic power characteristics, it is considered for the solution to be specified that the compressor should be usable for artificial respiration of a patient, wherein special artificial respiration parameters should be able to be implemented depending on the respective illness of the patient. Furthermore, such a compressor should be characterized by a simple design structure, taking into account known design structure principles when implementing the simple design structure, and by as low as possible manufacturing costs. Furthermore, it is desirable that a compressor based on the present application causes as little flow losses as possible in the air or gas guidance, at least in the frequently used operating range, and is designed to be easy to maintain.

[0013] Advantageous embodiments of the present application are the subject of the dependent claims and are explained in more detail in the subsequent description, partly with reference to the figures.

[0014] The present application relates to a compressor for conveying an air flow and / or a gas flow, with a housing, in the housing interior of which a compressor wheel is arranged in a rotatable manner and is connected to an electric motor by means of a drive shaft, an air flow and / or a gas flow being conveyed from an inlet arranged upstream on the suction side of the compressor wheel through a flow channel to an outlet arranged downstream on the pressure side of the compressor wheel when the compressor wheel is rotating. The outstanding compressor according to the present application is characterized in that the compressor wheel arranged in the housing interior is surrounded on the one hand at least partially by a collection housing for the air flow and / or gas flow which is pressed radially outwards and on the other hand by a cover element, the collection housing being preferably constructed in the form of a spiral and being arranged at least partially on the pressure side of the compressor wheel, the cover element being arranged at least partially on the suction side of the compressor wheel and being separated from the compressor wheel at least partially by a gap. Here, at least one decoupling element for damping and at least partially sealing the housing interior from the surroundings is arranged between the cover element and the collection housing on the one hand and between the functional components which are at least indirectly connected to the compressor wheel and the collection housing on the other hand, respectively.

[0015] It is important for the solution according to the application that the housing inner chamber, in which the compressor wheel is arranged in a rotatable manner, which is at least temporarily filled with the air or gas stream to be conveyed, is at least partially surrounded by an encapsulation having at least two components, a preferably helically configured collecting housing, the so-called spiral housing, and a cover element, wherein at least one decoupling element for damping and at least partially sealing the housing inner chamber against the surroundings is provided between the collecting housing and the cover element or between the collecting housing and a functional component which is adjacent to this collecting housing and is at least indirectly connected to the electric motor and / or the compressor wheel. The preferably helically configured collecting housing is thus vibrationally decoupled both against the functional component and against the cover element which is arranged upstream on the suction side of the compressor wheel, so that a damping of the occurring vibrations is achieved, for example, by using an elastic decoupling element. A transmission of vibrations from the cover element to the spiral housing but also from the adjacent functional component to the spiral housing is thus reliably prevented or at least minimized. The collecting housing which at least partially delimits the housing inner chamber is in this way decoupled in terms of possible transmission of vibrations both against the electric motor and the compressor wheel which is at least indirectly connected to this electric motor and thus ensures a reduction of the emitted sound emissions without having to provide an additional secondary housing for this purpose which surrounds the collecting housing which at least partially delimits the housing inner chamber, also referred to as the primary housing. By the selected decoupling, the transmission of vibrations which are generated by the electric motor and / or the compressor wheel and are emitted by the functional component, in particular the housing parts, is effectively significantly reduced. The main collecting housing itself does not act as an emission surface, since the collecting housing is decoupled from the sources of vibration and is even part of the encapsulation of the compressor according to the technical solution according to the application. The collecting housing here takes over the same function as the so-called secondary housing in the technical solutions disclosed by the prior art. It is thus important for the present application that the collecting housing is fixed at the adjacent components which can excite vibrations during the operation of the compressor indirectly by suitable decoupling elements which prevent or at least minimize the transmission of vibrations.

[0016] By providing the compressor wheel with a separate encapsulation and in combination with flexible and simultaneously relative to the surrounding environment sealing the housing interior between the encapsulation parts, i.e. between the cover element and the collecting housing and / or between the collecting housing and the adjacent functional component, on the one hand the transmission of vibrations emanating from the compressor wheel and / or the electric motor to the collecting housing is prevented, and on the other hand the gap losses in the housing interior between the suction side and the pressure side are still minimized. According to the invention, this is achieved in that on the suction side of the compressor wheel a cover element is arranged which is separated from the collecting housing by a decoupling element, the cover element being separated from the rotatably supported compressor wheel only by a small gap. Since the cover element provided according to the invention is not connected to the electric motor by a flexible suspension as disclosed in the prior art, the electric motor itself has a rigid connection to the compressor wheel by means of the drive shaft, so that a small tolerance can be ensured when implementing the invention.

[0017] The housing interior (with the compressor wheel rotatably supported therein) is according to the invention surrounded by an encapsulation having a cover element and a collecting housing as components, the collecting housing preferably being configured as a spiral housing. The functional component adjacent to the collecting housing and connected by a coupling element preferably relates to a part of the encapsulation of the electric motor and / or of the drive compressor wheel. It is also conceivable that the functional component is at least indirectly or directly connected to the electric motor. By means of the elastic decoupling element between the preferably spiral configured collecting housing and the functional component, the transmission of vibrations which are at least temporarily generated during operation by the structural elements moved by the electric motor, in particular the drive shaft and the compressor wheel fixed thereto, is reliably prevented or at least minimized. The functional component preferably has a sealing surface of circular or olive-shaped configuration, the decoupling element being fixed at the sealing surface, the decoupling element establishing an elastic, at least partially flexible connection between the functional component and the collecting housing. The decoupling element serves here both for preventing or at least minimizing the transmission of vibrations and for sealing the housing interior relative to the surrounding environment, the at least partially compressed air or gas stream conveyed by the compressor wheel being present in the housing interior.

[0018] In a particular embodiment of the invention, the cover element arranged on the suction side of the compressor wheel is designed in the form of a disc. Here, the disc has a passage inside the disc, the passage preferably having a disc-shaped cross-section and through which the air and / or gas stream drawn in due to the rotation of the compressor wheel enters into the inlet of the compressor.

[0019] According to a particular further embodiment of the application, the cover element is at least indirectly or directly connected to a flow guide unit which has at least one guide element, for example in the form of a guide vane, for guiding the air and / or gas flow coming out on the pressure side of the compressor wheel. Advantageously, the cover element is supported by the flow guide unit, wherein, in this interrelationship, it is conceivable that the cover element is connected on the side of the flow guide unit facing away from the gap between the cover element and the compressor wheel to a decoupling element arranged between the spiral housing and the functional component. In this case, it is ensured by the decoupling element that vibrations possibly occurring when the throughflow flows through the flow guide element are not transmitted to the collecting housing, so that sound emissions from the collecting housing by sound radiation through solids are reliably prevented or at least minimized.

[0020] According to a particular embodiment, the flow guide unit is configured in the form of a ring and has a plurality of guide vanes arranged along the circumference of the ring. Here, the compressor wheel is arranged in the interior of the flow guide unit in a rotatable manner such that, during operation, at least temporarily, the air and / or gas flow coming out on the pressure side from the compressor wheel at least partially occurs on the plurality of guide vanes. The stationary guide vanes are preferably not directly adjacent to the rotating compressor wheel in operation, wherein it has proven advantageous to configure the region between the compressor wheel and the guide vanes in the form of a diffuser. The diffuser is preferably designed according to flow parameters occurring in at least one operating point or operating region occurring at least frequently during operation of the compressor.

[0021] It is furthermore advantageous if the compressor wheel has a main blade extending at least almost radially from the outer circumference of the compressor wheel at least almost transversely through the entire cross section of the flow channel and at least two intermediate blades arranged between the main blade and designed to be shorter than the main blade. Both the main blade and the intermediate blade are designed, for example, curved and / or bent, such that the air and / or gas flow to be conveyed is compressed as efficiently as possible, in particular with minimized flow losses.

[0022] The compressor wheel designed as described before is characterized, in addition to particular efficiency in compressing air and / or gas, primarily in a low sound emission, since, due to the particular design of the main blade and the intermediate blade, the formation of vortices in the interior of the compressor wheel is reliably avoided. Furthermore, with a compressor wheel constructed in this way from a main blade and intermediate blades, it is ensured that, despite a small construction space, a high aerodynamic power is achieved.

[0023] According to a particularly advantageous development of the application, a compressor wheel is used which has an outer diameter of 29 to 34 mm, preferably 30 to 32 mm. Preferably, between 8 and 10, in particular between 9 and 13, main vanes are provided at the compressor wheel, between which at least two intermediate vanes are arranged each.

[0024] The intermediate vanes each extend in the central direction from the outer circumference of the compressor wheel, but are shorter than the main vanes and are preferably likewise curved and / or bent. In a particularly preferred embodiment, the intermediate vanes arranged between the main vanes are not equally long in the radial direction, have a different profile and / or have a different blade area. According to this particularly preferred embodiment, at least two intermediate vanes of a correspondingly different configuration are arranged between two main vanes of preferably the same configuration.

[0025] In another embodiment of the application, at least one inlet muffler is arranged upstream of the compressor wheel. The inlet muffler preferably has at least one spiral muffler. The flow cross section resulting from the spacing between the coils of the spiral and the spiral height should advantageously be greater than the inlet cross section of the compressor wheel by preferably about 25-35%, preferably about 30%. In general, it is advantageous for the spacing between the individual coils of the spiral to be kept small in order thus to minimize the sound emission that can be caused by flow noise and that emerges through the inlet. However, a reduction in the spacing of the spiral wall leads to an increase in the resulting structural height of the spiral muffler at the defined flow cross section. In order to be able to achieve a compact and as flat a configuration as possible, according to a particularly preferred development of the application, the inlet muffler has a spiral muffler with at least two separate spiral elements which are arranged at least partially staggered. It is conceivable in this interrelationship for the staggered nested spirals to have the same or different flow cross sections. However, the spacing of the spiral wall is halved when a second spiral is used, which significantly improves the sound-deadening properties of the spiral muffler while the outer dimensions are the same or at least similar.

[0026] However, inlet mufflers, in which the muffling is achieved by a cross-sectional narrowing and a deflection arranged in the flow channel, such as a spiral muffler, cannot be optimized in terms of maximum muffling, since both the cross-sectional narrowing and the deflection result in an increase in the flow momentum and thus in an undesired decrease in the gas. In contrast, a large flow cross section ensures a small flow resistance and thus a high efficiency. The design of the inlet muffler thus always requires a compromise between minimizing the sound emission and the pneumatic power. Theoretically optimal muffler is characterized in that the flow cross section is likewise largest at the maximum volume flow of the air or gas stream conveyed by the compressor, decreases with increasing throttling of the compressor and, at full throttling, when the volume flow thus assumes the value zero, completely closes the inlet.

[0027] According to a particularly preferred embodiment of the application, at least the previously described functionality is achieved at least approximately, i.e. the inlet muffler has at least one automatically closing valve element which opens and closes depending on the pressure difference applied to the valve. The valve is preferably actuated by the pressure difference applied to the valve. The valve element is thus advantageously designed in the form of a non-return valve which reliably prevents a backflow of air and / or gas from the flow channel of the compressor wheel. The valve element preferably has a valve disc which is designed in the form of a valve membrane.

[0028] In another particularly preferred embodiment, the desired opening behavior is thus set, i.e. the rigidity of the valve membrane used as a valve disc, the arrangement of the valve membrane and / or the fixation of the valve membrane is selected as required.

[0029] The valve element of the inlet muffler is preferably designed in such a way that it releases the largest flow cross section between the valve disc and the valve seat at the maximum volume flow, i.e. at the maximum pneumatic power of the compressor, and releases the smallest flow cross section at the maximum throttling operation of the compressor. The noise emitted by the inlet is thus minimized as much as possible during operation and thus the maximum sound insulation is achieved.

[0030] According to a particularly preferred embodiment, a plurality of such valve elements having different opening behaviors are connected in series, so that the characteristic line of the compressor can be optimized as required, for example to achieve constant compression in a predetermined volume flow range.

[0031] At least one of the aforementioned valve elements can advantageously be used, individually or jointly, with a spiral silencer designed according to the aforementioned embodiments, for minimizing the sound coming through the inlet, in particular for preventing or at least reducing the sound emissions produced by the compressor wheel and coming through the inlet against the flow direction of the conveyed air and / or gas stream. These sound emissions through the inlet typically become stronger if the compressor wheel is throttled at a constant rotational speed level. It is thereby known that the sound emissions assume a maximum value in operating points in which the compressor is not through-flowed. BRIEF DESCRIPTION OF DRAWINGS

[0032] The application is explained in more detail below by means of specific embodiments with reference to the drawings, without limiting the general inventive idea.

[0033] Figure 1 A schematic cross-sectional view of a compressor with a primary housing and a secondary housing is shown, which is disclosed by the prior art;

[0034] Figure 2 A schematic cross-sectional view of a compressor designed according to the application is shown;

[0035] Figure 3 A cross-sectional view of a compressor designed according to the application is shown;

[0036] Figure 4 A cross-sectional view of a flow guide unit of a compressor designed according to the application is shown;

[0037] Figure 5 A perspective view and a top view of a compressor wheel of a compressor designed according to the application are shown;

[0038] Figure 6 A perspective view of an inlet silencer designed as a spiral silencer with a split spiral is shown;

[0039] Figure 7 A perspective view of an inlet silencer designed as a spiral silencer with two intermeshing split spirals is shown; and

[0040] Figure 8 A cross-sectional view of an inlet silencer with a check valve in the open and closed operating position is shown. DETAILED DESCRIPTION

[0041] Figure 1First, a compressor 1 for an artificial respiration or anesthesia device as known in the prior art is shown. The compressor 1 has an electric motor 5 that drives a compressor impeller 6 via a drive shaft 4 according to the power parameters required for artificial respiration of the patient. The compressor impeller is rotatably supported in a collection housing 2, which is designed as a helical casing, also known as a primary casing, into which air enters during operation through a central inlet 8. The compressor impeller 6 is designed as a radial compressor impeller, directly driven by the electric motor 5 according to the required pneumatic power.

[0042] During operation, air is drawn in through the central inlet 8, radially distributed outward by the rotation of the compressor impeller 6, collected in the spiral collection housing 2, and delivered to the outlet 10. To minimize noise emissions during operation, the compressor is surrounded by a second housing 27, the so-called secondary housing, which also has inlets and outlets for the air and / or gas flow to be delivered. To prevent vibration transmission, the unit consisting of the electric motor 5, the compressor impeller 6, and the primary housing 2 is clamped in the secondary housing 27 with a flexible, soft decoupling element 15. The additional housing in the form of the secondary housing 27 is therefore particularly necessary because the connection between the electric motor 5 and the compressor impeller 6, and between the electric motor 5 and the primary housing 2, is constructed to be rigid, so vibrations caused by operation, especially at high motor speeds, are transmitted almost undisturbed to all connected housing parts and thus radiated into the surrounding environment 16, depending on the implementation of the connection. This structural design with two separate housings 2, 27 precludes a compact construction of the corresponding compressor.

[0043] In addition, by Figure 1 As can be seen, the primary housing 2, as an integral collecting housing, surrounds the inner housing chamber 3, which has a compressor impeller 6 arranged within the inner housing chamber. Here, on the suction side 7 of the compressor impeller 6, there is a small gap 13 between the cover area of ​​the primary housing 2 and the compressor impeller 6. This gap 13 must be kept as small as possible to prevent or at least minimize bypass flow from the pressure side 9 to the suction side 7, as such bypass flow reduces the efficiency of the compressor. On the other hand, the size of said gap 13 is set in such a way that contact between the compressor impeller 6 and the cover area of ​​the collecting housing 2 is reliably prevented under any operating conditions, especially when the speed increases and / or the compressor impeller 6 becomes hot. It is thus immediately apparent that the contradiction between the gap 13 between the cover area of ​​the collecting housing 2 and the compressor impeller 6, and on the one hand, the fixed position required for this of the cover area of ​​the collecting housing, and on the other hand, the minimum height requirement of the flexible suspension structure of the collecting housing to ensure the most effective sound insulation, indicates a significant structural design problem.

[0044] existFigure 2 A compressor designed according to the application is shown in a schematic sectional view. The compressor has a compressor wheel 6 which is rotatably supported in a housing inner chamber 3 and which is driven by an electric motor 5 via a drive shaft 4. The compressor wheel 6 is rotated in accordance with a desired air flow and / or gas flow of the electric motor 5, the air flow and / or gas flow being thereby conveyed from an inlet 8 arranged upstream on a suction side 7 of the compressor wheel 6 via a flow channel to an outlet 10 arranged downstream on a pressure side 9 of the compressor wheel 6. The housing inner chamber 3 and the compressor wheel 6 arranged therein are surrounded by a collecting housing 2 of spiral configuration, which can also be referred to as a spiral housing, and a cover element 12 of disc shape, wherein the cover element 12 defines the housing inner chamber 3, in particular on the suction side 7, and the collecting housing 2 defines the housing inner chamber 3, mainly on the pressure side 9.

[0045] According to the application, the enclosing structure surrounding the housing inner chamber 3 thus consists of two parts, namely the spiral collecting housing 2 and the disc-shaped cover element 12. In order to avoid the transmission of vibrations from the compressor wheel 6 and / or from the electric motor 5 to the collecting housing 2, decoupling elements 15 are arranged both between the cover element 12 and the collecting housing 2 and between the collecting housing 2 and a functional component 14, which in this case relates to a part of the motor housing. The enclosing structure surrounding the housing inner chamber 3 with the compressor wheel 6 arranged therein is thus divided into two parts, namely the cover element 12 above the compressor wheel 6 and the spiral collecting housing 2, which can also be referred to as a spiral housing or scroll. According to the application, the cover element 12 is designed as a disc, wherein the inlet 8 for the air flow and / or gas flow is centrally located in the disc. On the inlet side, the cover element 12 is connected to the collecting housing 2 by means of flexible decoupling elements, thus reliably preventing or at least minimizing the transmission of vibrations from the cover element 12. Furthermore, a seal of the housing inner chamber 3 with respect to the surroundings is ensured by means of the decoupling elements 15 provided in this region. Figure 2 According to the embodiment shown, the cover element 12 is designed as a disc, wherein the inlet 8 for the air flow and / or gas flow is centrally located in the disc. On the inlet side, the cover element 12 is connected to the collecting housing 2 by means of flexible decoupling elements, thus reliably preventing or at least minimizing the transmission of vibrations from the cover element 12. Furthermore, a seal of the housing inner chamber 3 with respect to the surroundings is ensured by means of the decoupling elements 15 provided in this region.

[0046] On the side of the cover element 12 facing away from the inlet 8, this cover element is supported on a flow guide unit 17. The flow guide unit 17 is in turn indirectly or directly supported on the functional component 14, for example a housing component of the electric motor 5, on the side facing away from the cover element 12. In this way, it is ensured that the cover element 12 is vibrationally decoupled from the collecting housing 2 by means of the decoupling elements 15 on the one hand and that there is a rigid connection to the functional component 14 on the other hand, so that a small gap 13 between the cover element 12 and the compressor wheel 6 can be realized without the risk of contact during operation.

[0047] The flow guide unit 17 on which the cover element 12 is supported is designed according to the application as a disc, wherein the flow guide unit 17 is supported on the functional component 14, for example a housing component of the electric motor 5, on the side facing away from the cover element 12. In this way, it is ensured that the cover element 12 is vibrationally decoupled from the collecting housing 2 by means of the decoupling elements 15 on the one hand and that there is a rigid connection to the functional component 14 on the other hand, so that a small gap 13 between the cover element 12 and the compressor wheel 6 can be realized without the risk of contact during operation. Figure 2The shown embodiment is arranged on the pressure side of the compressor wheel 6, so that the air and / or gas flow coming out of the compressor wheel 6 impinges on the guide unit 17 and is at least partially diverted by this guide unit. The shown guide unit 17 has stationary guide vanes 18 which are not directly adjacent to the rotating compressor wheel 6 in motion. The area between the compressor wheel 6 and the guide vanes 18 constitutes the most frequently used working area of the compressor in the form of a diffuser.

[0048] The schematic diagram of Fig. 1 shows a compressor 1 with a housing 2, a cover element 12, a motor 5, a compressor wheel 6, a guide unit 17 with guide vanes 18 and a diffuser 19. The housing 2 is designed as a collecting housing and is arranged in the form of a housing inner chamber 3 which is sealed against the surroundings 16. The cover element 12 is arranged on the housing 2 and is designed as a cover element inner chamber 4 which is sealed against the surroundings 16. The motor 5 is arranged in the housing inner chamber 3 and is designed as an electric motor. The compressor wheel 6 is arranged in the housing inner chamber 3 and is designed as a compressor wheel which is driven by the motor 5. The guide unit 17 is arranged in the housing inner chamber 3 and is designed as a guide unit which is driven by the compressor wheel 6. The diffuser 19 is arranged in the housing inner chamber 3 and is designed as a diffuser which is driven by the guide unit 17. Figure 2 It is apparent from the schematic diagram of Fig. 1 that the separation between the cover element 12 and the collecting housing 2 and between the collecting housing 2 and the functional component 14 which forms a part of the motor housing here is connected by decoupling elements 15 which on the one hand ensure the vibration-technical decoupling of the components which are adjacent on both sides and on the other hand seal the housing inner chamber 3 against the surroundings 16 with a pressure load. Due to the provided decoupling, in particular the vibrations generated by the electric motor 5 are not transmitted to the collecting housing 2 which directly delimits the housing inner chamber 3 or at least the transmission of vibrations is substantially reduced. According to the embodiment shown in Fig. 1, the collecting housing 2 takes over the function which in the technical solutions known from the prior art is taken over by a secondary housing 27 which is arranged as an additional enveloping structure as shown in Fig. 2. Due to the provision according to the technical solution of the application, a compressor with a smaller size can be provided, the aerodynamic power of which can even be increased compared to the known solutions with a suitable dimensioning and implementation of the guide vanes 18 and the diffuser for the selected working area. Figure 2 According to the embodiment shown in Fig. 1, the collecting housing 2 takes over the function which in the technical solutions known from the prior art is taken over by a secondary housing 27 which is arranged as an additional enveloping structure as shown in Fig. 2. Due to the provision according to the technical solution of the application, a compressor with a smaller size can be provided, the aerodynamic power of which can even be increased compared to the known solutions with a suitable dimensioning and implementation of the guide vanes 18 and the diffuser for the selected working area. Figure 1 According to the embodiment shown in Fig. 1, the collecting housing 2 takes over the function which in the technical solutions known from the prior art is taken over by a secondary housing 27 which is arranged as an additional enveloping structure as shown in Fig. 2. Due to the provision according to the technical solution of the application, a compressor with a smaller size can be provided, the aerodynamic power of which can even be increased compared to the known solutions with a suitable dimensioning and implementation of the guide vanes 18 and the diffuser for the selected working area.

[0049] Figure 3A cross-sectional view of a compressor designed according to the present invention is shown, which has a helical collection housing 2, a cover element 12, and a decoupling element 15. A compressor impeller 6, rotatably supported, is arranged in the housing chamber 3 and is driven by an electric motor 5 via a drive shaft 4. Importantly, the encapsulation structure for the housing chamber 3 and the compressor impeller 6 rotatably supported in the housing chamber is formed by the collection housing 3 and the cover element 12. The decoupling element 15 is provided both between the collection housing 2 and the cover element 12 and between the collection housing 2 and the functional component 14. The decoupling element ensures both the vibrational decoupling of the components adjacent to the decoupling element 15 and the sealing of the pressurized housing chamber 3 relative to the surrounding environment 16. The decoupling element 15, arranged on the motor side, is constructed such that vibrational decoupling is achieved even at the separation point between the collection housing 2 and the functional component 14 (here, part of the housing of the electric motor 5). Therefore, this decoupling element 15 reliably ensures that vibrations generated by the compressor impeller 6 and, in particular, by the electric motor 5 are not transmitted, or only slightly transmitted, to the collection housing 2 surrounding the inner chamber 3. Thus, the radiation of interfering sound is reliably avoided, or at least significantly reduced. The flow guiding unit 17 is connected to the functional member 14 on the motor side, at least indirectly, by at least one screw 29. This screw 29 advantageously functions as an adjusting screw, thus allowing the width of the gap 13 between the cover element 12 and the flow guiding unit 17 to be set by properly tightening and / or loosening the screw 29.

[0050] In addition, Figure 3 In the structural unit shown, an inlet 8 is provided on the suction side 7. When the compressor impeller 6, arranged in the housing chamber 3, rotates, airflow and / or gasflow flows through this inlet along the direction of the compressor impeller 6. As the compressor impeller 6 rotates, this suctioned airflow and / or gasflow is ultimately compressed radially outward by the compressor impeller 6 and guided radially outward along the wall of the collection housing 2 by the guide vanes 18 of the guide element 17, which is connected to or alternatively designed integrally with the cover element 12. The compressed airflow and / or gasflow then exits from the compressor's collection housing 2 through the outlet 10 and is, for example, delivered to a patient undergoing mechanical artificial respiration. The cover element on the suction side is designed in a disc shape, with the inlet 8 centrally located at the center of the disc. The cover element 12 is supported downward on a functional member 14 by the guide element 17, which in this case relates to the housing portion of the electric motor 5. In the region of the inlet 8, a decoupling element 15 is provided at the separation point between the cover element 12 and the collection housing 2. This decoupling element 15 ensures that vibration is not transmitted to the collection housing 2, and also ensures the seal of the pressurized housing chamber 3 relative to the surrounding environment 16.

[0051] The flow guide unit 17 has on the pressure side 9 a plurality of guide vanes 18 distributed radially on the circumference, which divert the air flow and / or gas flow pressed radially outwards by the compressor wheel 6 in a suitable manner. The region between the pressure side of the compressor wheel 6 and the guide vanes 18 is configured as a diffuser for the frequently occurring operating regions. Figure 4 This special flow guide unit 17, which is configured annularly and has a plurality of guide vanes 18 distributed on the outer circumference, is shown in a perspective sectional view, the sectional plane here extending horizontally through the flow guide unit 17. The flow guide unit 17 is designed in such a way that the cover element 12, as specified in the present application, can be supported on it. The flow guide unit 17 for this purpose has a suitable abutment contour or can alternatively be designed integrally with the cover element 12. In any case, the flow guide unit 17 establishes an indirect or direct connection between the cover element 12 and the functionally configured component 14 arranged on the motor side.

[0052] Figure 5 A particularly configured compressor wheel 6, which can be used in an advantageous manner in the compressor configured according to the application, is shown in a perspective view a) and in a top view b). During rotation of this compressor wheel 6, the air flow and / or gas flow is conveyed radially outwards by means of the vanes 19, 20. The shown compressor wheel 6 firstly has main vanes 19, which extend at least almost completely from the outer circumference of the compressor wheel to the centre of the compressor wheel, where it can be fixed at the drive shaft of the electric motor. According to the embodiment shown in Figure 5 The compressor wheel 6 has 10 main vanes 19 according to the embodiment shown in Figure 5 According to the embodiment shown in

[0053] Due to this embodiment of the intermediate vanes 20, the formation of vortices between the main vanes 10 is advantageously prevented or at least strongly minimised, and thus likewise at least reduced sound emissions which would otherwise arise therefrom.

[0054] Figure 5 The compressor wheel preferably has an outer diameter of 30 to 32 mm. It is furthermore advantageous to provide 9 to 13 main vanes 19, between which two intermediate vanes 20 of different dimensioning are arranged as explained previously.

[0055] Advantageously, the maximum height of the main blade 19 assumes a value between 5 and 6 and the upper edge of the main blade 19 is at least partially inclined in the direction of the outer circumference of the compressor wheel 6. An angle between 75° and 80° appears reasonable here. Important for the efficient operation of the compressor wheel 6 is first of all the embodiment of the blade channel. According to the shown embodiment, the dimensions are chosen such that the outlet cross section is about 30% larger than the inlet cross section.

[0056] In Figure 6 the inlet muffler 21 designed as a spiral muffler with a spiral element 22 arranged therein is shown. By reducing the flow cross section in the interior of the inlet muffler 21 and by a deflection of the flow, the sound emission in the direction of the inlet of the inlet muffler 21 is minimized. The flow cross section of the inlet muffler 21 is dimensioned such that it is about 30% larger than the inlet cross section of the compressor. If the spacing between the individual coils of the spiral element 22 is kept small, the emission of flow noise coming back through the inlet of the compressor can be minimized. However, a too strong reduction of the flow cross section in the inlet muffler 2 is a great disadvantage depending on the individual required aerodynamic power of the compressor. Therefore, in order to guarantee the defined flow cross section despite the reduced wall spacing in the spiral element 22, the resulting structural height of the inlet muffler 21 has to be enlarged, and thus the inlet muffler quickly becomes larger. Therefore, in order to achieve a compact and flat construction form of the inlet muffler, the spiral element 22 arranged inside can thus be divided in a preferred manner into two interleaved nested partial spirals as shown in Figure 7 In Figure 7 the spiral element composed of two partial spirals shown, has the same flow cross section as the spiral element shown in Figure 6 However, if the wall spacing is halved, the muffling behavior against flow noise coming from the inlet is significantly improved at similar outer dimensions of the inlet muffler 21.

[0057] However, the inlet muffler 21 in which the muffling is achieved by a cross section narrowing and a deflection arranged in the flow channel, for example Figure 6 and 7The spiral silencer shown in the prior art can not be optimized in terms of maximum sound reduction, since any narrowing of the cross section, lengthening or turning of the flow channel leads to an increase in flow resistance and thus to an undesired reduction in aerodynamic power. In contrast, a large flow cross section and a short flow channel ensure a small flow-technical resistance and thus a high efficiency. The design of the inlet silencer thus always requires a compromise between minimizing sound emission and aerodynamic power. Theoretically optimal silencers are characterized in that the flow cross section is also largest at the largest volume flow of the air or gas stream conveyed by the compressor, becomes smaller with increasing throttling of the compressor and is completely closed at full throttle, when the volume flow thus assumes the value zero.

[0058] Thus in combination Figure 8 In the following, a special possibility is explained for implementing an inlet silencer 21 for a compressor designed according to the application. The functionality explained before is here achieved at least approximately by the fact that the inlet silencer 21 has at least one automatically closing valve element 23 which opens and closes depending on the pressure difference applied at the valve. The actuation of the valve element 23 is here preferably based on the pressure difference applied at the valve 24. The valve element 23 is thus advantageously designed in the form of a non-return valve which reliably prevents a backflow of air and / or gas from the flow channel of the compressor wheel 6. Figure 8 The valve element shown in the prior art has a valve disc 24 which has a valve membrane 28.

[0059] The necessary opening behavior is thus set by the fact that the rigidity of the valve membrane 28 used, its shape, its arrangement in the flow channel and / or the fixation of the valve membrane are selected as required.

[0060] The valve element 24 of the inlet silencer 21 shown is thus designed such that it releases a maximum valve opening 26 for a maximum flow cross section between the valve disc 24 and the valve seat 25 at the maximum volume flow, i.e. at the maximum aerodynamic power of the compressor, and a minimum valve opening 26 for a minimum flow cross section in the operation of the compressor at maximum throttle. The maximum possible minimization of the sound emitted by the inlet is thus achieved during operation and thus the maximum possible soundproofing.

[0061] In this interrelationship, Figure 8 a) an operating state is shown in which the valve element 23 is open and the valve disc 24 is lifted from the valve seat 25, so that the valve opening 26 is at least partially released. In contrast, Figure 8 b) an operating state is shown in which the valve element 24 is closed and the valve disc 25 rests on the valve seat 26 along its outer circumference.

[0062] It is conceivable in principle to provide the inlet muffler 21 with a valve element 24 as explained previously or to use at least two such valve elements. If several such valve elements 24 with different opening characteristics are connected in series, then the characteristic line of the compressor can be optimized as required, and it is thus possible to achieve, for example, a constant compression over a predetermined volume flow range.

[0063] At least one of the aforementioned valve elements 24 can likewise be used alone or together with a spiral muffler as shown in Figure 6 and 7 for minimizing the sound emissions through the inlet 7, in particular for preventing or at least reducing the sound emissions from the inlet 8 in the direction of flow of the conveyed air and / or gas flow, which are generated by the compressor wheel 6. These sound emissions through the inlet 8 generally become stronger if the compressor wheel 6 is throttled at a constant rotational speed level. It follows that the sound emissions assume their greatest value in operating points in which the compressor is not being bypassed.

[0064] List of reference signs

[0065] 1 compressor

[0066] 2 collecting housing

[0067] 3 housing interior

[0068] 4 drive shaft

[0069] 5 electric motor

[0070] 6 compressor wheel

[0071] 7 suction side

[0072] 8 inlet

[0073] 9 pressure side

[0074] 10 outlet

[0075] 11 flow channel

[0076] 12 cover element

[0077] 13 gap

[0078] 14 functional component

[0079] 15 decoupling element

[0080] 16 ambient environment

[0081] 17 flow guide unit

[0082] 18 guide vane

[0083] 19 main vane

[0084] 20 intermediate vane

[0085] 20a longer intermediate vane

[0086] 20b shorter intermediate vane

[0087] 21 inlet muffler

[0088] 22 helical element

[0089] 23 valve element

[0090] 24 valve disc

[0091] 25 valve seat

[0092] 26 valve opening

[0093] 27 secondary housing

[0094] 28 valve membrane

[0095] 29 screw

Claims

1. Compressor (1) for conveying an air flow and / or a gas flow, with a housing (2), in the housing interior (3) of which a compressor wheel (6) is arranged which is rotatably supported and connected to an electric motor (5) by means of a drive shaft (4), the air flow and / or the gas flow being conveyed from an inlet (8) arranged upstream on a suction side (7) of the compressor wheel (6) through a flow channel (11) to an outlet (10) arranged downstream on a pressure side (9) of the compressor wheel (6) when the compressor wheel is rotated, characterized in that the compressor wheel (6) arranged in the housing interior (3) being at least partially surrounded by the housing and a cover element (12), the housing being designed as a collecting housing (2) for the air flow and / or the gas flow coming out of the compressor wheel (6) and being arranged at least partially on the pressure side (9) of the compressor wheel (6), the cover element being arranged at least partially on the suction side (7) of the compressor wheel (6) and being separated from the compressor wheel (6) at least partially by a gap (13), wherein at least one decoupling element (15) is arranged between the cover element (12) and the collecting housing (2) and between a functional component (14) which is at least indirectly connected to the compressor wheel (6) and / or the electric motor (5) and the collecting housing (2) respectively for damping and at least partial sealing of the housing interior (3) from the surroundings (16).

2. The compressor of claim 1, wherein The functional component (14) is part of the housing and / or part of an encapsulation of the electric motor (5) and / or is indirectly or directly connected to the electric motor (5).

3. A compressor according to claim 1 or 2, characterised in that The cover element (12) is designed in the form of a disc which has a channel for the air flow and / or the gas flow inside the disc.

4. The compressor according to claim 1 or 2, characterized in that The cover element (12) is at least partially indirectly or directly connected to a flow guide unit (17) which has at least one guide vane (18) for guiding the air flow and / or the gas flow coming out on the pressure side (9) of the compressor wheel (6).

5. The compressor of claim 4, wherein The flow guide unit (17) is constructed in the form of a ring having a plurality of guide vanes (18) arranged on the ring face, and the compressor wheel (6) is arranged in the interior of the flow guide unit (17) in such a way that the air flow and / or the gas flow coming out on the pressure side (9) of the compressor wheel (6) emerges at least partially onto the plurality of guide vanes (18).

6. The compressor according to claim 1 or 2, characterized in that The compressor wheel (6) has at least one main blade (19) which extends transversely through at least the entire cross section of the flow channel (11) in the radial direction from the outer circumference of the compressor wheel (6) and at least two intermediate blades (20) arranged between the main blades (19) respectively and designed to be shorter than the main blades.

7. The compressor of claim 6, wherein The intermediate blades (20) arranged between two main blades (19) are not equally long in the radial direction, have different profiles and / or are not equally large in blade area.

8. The compressor of claim 1, wherein At least one inlet muffler (21) is arranged upstream of the compressor wheel (6).

9. The compressor of claim 8, wherein The inlet muffler (21) is designed as a spiral muffler.

10. A compressor according to claim 8 or 9, characterised in that The inlet muffler (21) is designed as a spiral muffler with at least two separate spiral elements (22) arranged at least partially staggered.

11. The compressor according to claim 1 or 2, characterized in that At least one valve element (23) is arranged upstream of the compressor wheel (6), which opens in the flow direction of the air and / or gas stream on the basis of a pressure difference caused by the rotation of the compressor wheel (6).

12. The compressor of claim 11, wherein The valve element (23) has a movably supported valve membrane as valve disc (24).

13. Artificial respiration or anesthesia apparatus with a compressor (1) according to at least one of the preceding claims 1 to 12.

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