VENTILATION DEVICE AND METHOD FOR PROVIDING A BREATHING GAS

Description

[0001] The disclosure relates to a pumping device in the sense of a positive displacement pump, in particular designed to convey gases.

[0002] Furthermore, the disclosure relates to a device for ventilation comprising such a pumping device.

[0003] Furthermore, the disclosure relates to a method for providing breathing gas using a ventilation device.

[0004] When mechanically ventilating patients using ventilation devices, there are various special requirements for effective implementation of ventilation.

[0005] In extreme ventilation situations, for example at a minute volume V = 10 L / min and a maximum pressure increase Δp = 60 hPa, the average pneumatic power is P average = V * Δp= 1 W, which means that the pneumatic power requirement is low. The requirements are exacerbated by intermittent operation, where a short inspiration is accompanied by rapid pressure increases and high flows. The necessary peak flows of up to V = 180 L / min and pressure increases of up to Δ̇p = 180 hPa / s require higher pneumatic peak power, but the average pneumatic power remains in a low range of a few watts.

[0006] To generate the required flows and pressures, known ventilation devices typically utilize blowers that draw in air through an inlet and expel it through an outlet using a fan impeller rotating within a housing. Such blowers offer a variety of advantages, including a compact and simple design, high flow performance, and high dynamics, making them a virtually ideal pressure source. However, a large rotational speed range is necessary to build pressure, their suitability as a flow source is rather limited, the highly turbulent flow of the escaping fluid complicates downstream flow measurement, and the average overall pneumatic efficiency is well below 10%. In detail, rapid increases in speed with associated increases in pressure lead to a significant change in the rotational energy stored in the fan impeller, which requires high power levels.These required power levels range above 40 W and can be significantly higher if very rapid pressure increases are required. At high speeds, there is also a high static power requirement. Overall, the use of fans in ventilation devices generates a great deal of heat that must be dissipated, making cooling measures essential.

[0007] The state of the art includes, as alternatives to the blower, in particular piston pumps and diaphragm pumps for use in ventilation devices. Although these pumps allow for reduced turbulence of the outflowing fluid and less heat loss, due to their design they place particularly high demands on component tolerances, so that the production costs for correspondingly precise dimensioning of the components are increased.

[0008] An object of the disclosure is to provide a device for ventilation with a pumping device which has improved properties with regard to power consumption and heat dissipation compared to a fan.

[0009] An object of the invention is to provide a device for ventilation with a pumping device which enables lower turbulence of the outgoing fluid compared to a blower.

[0010] This object is achieved according to the invention by a device for ventilation according to claim 1 and by a method according to claim 11.

[0011] A further object of the disclosure is to provide a device for ventilation with a pumping device which places lower demands on the component tolerances.

[0012] Advantageous embodiments of the invention are specified in the subclaims.

[0013] The features of a pumping device disclosed below are part of the invention both individually and in all possible combinations.

[0014] A pumping device according to the disclosure is designed as a positive displacement pump and has at least one pumping chamber and a rotor arranged in each pumping chamber.

[0015] The pump chamber is arranged in a housing and is designed as a stator of the pump device.

[0016] The pumping chamber has an inlet and an outlet through which a fluid can flow into or out of the pumping chamber.

[0017] The rotor is movable within the pump chamber along the inner wall of the pump chamber.

[0018] In one embodiment of the disclosure, the rotor is rotationally movable within the pumping chamber, in the sense that the position of the rotor within the pumping chamber can be changed, but not its orientation.

[0019] In one embodiment of the invention, the rotor or a point of the rotor is movable along an orbital path.

[0020] In one embodiment of the disclosure, the rotor is mounted eccentrically on a rotatable shaft of a drive and is decoupled from rotation by means of a decoupling device, so that an orbital movement of the rotor can be implemented.

[0021] In one embodiment of the disclosure, the decoupling device is designed as a rolling bearing.

[0022] The rotor is movable within the pumping chamber in such a way that a suction chamber can be formed in the pumping chamber behind the rotor in the direction of movement, into which a fluid can be drawn through the inlet by the movement of the rotor. A pressure chamber can be formed within the pumping chamber in front of the rotor in the direction of movement, from which the fluid can be pumped out of the pumping chamber via the outlet by the movement of the rotor.

[0023] The suction chamber is defined as the volume of the pumping chamber that has a connection to the inlet, depending on the angular position of the rotor in the pumping chamber minus the volume of the rotor, and the pressure chamber is defined as the volume of the pumping chamber that has no connection to the inlet, minus the volume of the rotor.

[0024] In one embodiment of the disclosure, the inlet and outlet of the pumping chamber are arranged on a common channel connected to the pumping chamber. The channel is divided by a separating element into a region associated with the inlet and an area associated with the outlet.

[0025] In one embodiment of the disclosure, the separating element is connected to the rotor.

[0026] In one embodiment of the disclosure, the separating element is designed as a connecting rod that is at least partially shaped like a stem and is connected to the rotor.

[0027] In a preferred embodiment of the disclosure, the connecting rod connected to the rotor projects from the pumping chamber into the region of the inlet and outlet of the pumping chamber and seals the inlet from the outlet.

[0028] In one embodiment of the disclosure, the connecting rod of the rotor is linearly guided at the end applied to the remaining rotor.

[0029] In one embodiment of the disclosure, the stator, in particular the wall of the pumping chamber, is made of a metal, so that high dimensional stability and thermal conductivity are provided.

[0030] In a preferred embodiment of the disclosure, the wall of the pumping chamber is formed from aluminum, which, in addition to high dimensional stability and thermal conductivity, has a relatively low mass.

[0031] In one embodiment of the disclosure, the rotor is formed from a sliding plastic, so that low friction is realized between the rotor and the inner wall of the pump chamber.

[0032] The course of the flow of the fluid flowing out of the outlet of the pump chamber is directly coupled to the course of the volume of the suction or pressure chamber of the pump device as a function of the angular position of the rotor within the pump chamber.

[0033] In a preferred embodiment of the disclosure, the rotor has at least one cavity to reduce the mass of the rotor. The lower the mass of the rotor, the lower the energy required to adjust the rotor's running speed.

[0034] In a preferred embodiment of the disclosure, the rotor is designed in relation to the inner wall of the pumping chamber such that, on the orbital movement path of the rotor realized with the aid of the eccentric drive, it has two points of contact with the inner wall of the pumping chamber in exactly one position on the movement path in cross section, while the rotor has only one point of contact with the inner wall of the pumping chamber in all other positions in cross section.

[0035] Depending on the three-dimensional design of the rotor and the pumping chamber, there is either one contact line or two contact lines depending on the position of the rotor. In a disk-like structure, in which the rotor and the pumping chamber each extend with a constant surface area over a height h, the contact lines are straight lines or segments of straight lines.

[0036] In a preferred embodiment of the disclosure, the separating element is arranged in the circumferential direction of the rotor between the two contact points of the rotor and the inner wall of the pump chamber, wherein the smaller distance between the contact points is decisive in the circumferential direction.

[0037] In a particularly preferred embodiment of the disclosure, in the position in which the rotor has two points of contact with the inner wall of the pumping chamber, both the path from the inlet and the path from the outlet into the remaining volume of the pumping chamber are blocked, so that a volume is enclosed within the pumping chamber.

[0038] The position at which the rotor and the inner wall of the pumping chamber have two points of contact is defined as the zero position, or 0° angular position, with respect to the orbital trajectory. The angle increases depending on the rotor's position in its direction of motion until the zero position is reached again at an angular position of 360°.

[0039] In one embodiment of the disclosure, at least one spring is arranged in the region of the rotor, by means of which the rotor can be pressed against the inner wall of the pumping chamber, thus improving sealing at the at least one contact point between the rotor and the inner wall of the pumping chamber. This, in particular, enables higher manufacturing tolerances.

[0040] In another embodiment of the disclosure, the housing wall is designed such that the housing wall is resilient against a fixedly mounted rotor, so that in particular higher manufacturing tolerances are possible.

[0041] In one embodiment of the disclosure, the housing wall of the pumping chamber is formed slightly smaller than the ideal contour for the corresponding rotor and can be pushed slightly outwards by the rotor at the contact point(s).

[0042] In a further embodiment of the disclosure, the housing of the pumping chamber has fins that protrude inwardly into the pumping chamber. These fins extend transversely to the direction of movement of the rotor in the pumping chamber and contact the rotor in the region of the contact point(s). The pressure generated in the pumping chamber presses the fins against the rotor, whereby the contact pressure of the fins is very low, with no significant initial pressure.

[0043] In a further embodiment of the disclosure, a resilient mounting of the rotor and one of the above-described configurations of the housing of the pump chamber are combined with one another.

[0044] In a preferred embodiment of the disclosure, the shape of the pumping chamber and the rotor are matched to one another in such a way that, at a constant speed of the rotor, a jump-free course of the flow of the pumped fluid at the outlet of the pumping chamber is realized.

[0045] In a preferred embodiment of the disclosure, the shape of the pumping chamber and the rotor are matched to one another in such a way that, at a constant speed of the rotor, an approximately sinusoidal course of the flow of the pumped fluid is realized at the outlet of the pumping chamber, wherein the minimum of the flow is approximately 0 (no flow in the opposite direction).

[0046] In one embodiment of the disclosure, the rotor is circular. However, due to the thickness of the partition between the inlet and outlet, realized in embodiments of the invention by the separating element designed, for example, as a connecting rod, the fluid flow pattern at the outlet deviates slightly from a sine curve.

[0047] The thinner the separating element or the connecting rod stem, the closer the fluid flow path at the outlet is to a sinusoidal shape. In embodiments of the invention, the separating element or connecting rod is therefore not rigid, but rather designed as a thin separating layer, which, at the end facing away from the rotor, is connected to the housing of the pump device, sealing the inlet from the outlet.

[0048] The separating element or connecting rod and / or the sealing connection between the separating element or connecting rod and the housing is designed to be flexible so that the movement of the rotor on the orbital path is not disturbed.

[0049] The volume that can be pumped by the pumping device in one revolution of the rotor depends on the rotor's eccentricity, with the pumped volume increasing with increasing eccentricity. This is due to the fact that the rotor's obturator path lengthens with increasing eccentricity, so the size of the pumping chamber must also be adjusted accordingly.

[0050] A disadvantage of a circular rotor is that only a small eccentricity is possible to achieve the most sinusoidal flow pattern of a fluid flowing out of the outlet, resulting in only a small pump volume. To address these problems, the shape of the rotor is adapted away from a circle in preferred embodiments of the invention.

[0051] In a preferred embodiment of the disclosure, the rotor has a circular basic shape, which is extended by circles arranged laterally adjacent to the separating element and partially extending beyond the circular basic shape of the rotor, each circle having a smaller diameter than the circular basic shape. The transitions between the basic shape and the smaller circles are designed to be smooth, at least on the sides facing away from the separating element.

[0052] In a further embodiment of the disclosure, the rotor according to the above embodiment has an elliptical basic shape instead of a circle as its basic shape, wherein the half of the ellipse facing the separating element is modified by two circles that partially overlap, and the transition of the ellipse into the circles is designed to be smooth.

[0053] In another embodiment of the disclosure, the shape of the rotor is formed according to a spline function.

[0054] Spline functions are advantageous for shaping the runner because they enable a curve progression without jumps. By generating a spline function in Cartesian coordinates and converting it to polar coordinates (radius versus angle), any number of jump-free runner curves can be created, which can then be further optimized with regard to the flow progression.

[0055] In one embodiment of the invention, the approximately sinusoidal course of the outflowing fluid is realized by an approximately sinusoidal free cross section in the region of the outlet or the connection of the outlet to the pump chamber during the rotation of the rotor in the pump chamber.

[0056] In preferred embodiments of the invention, the shape of the rotor and the shape of the pumping chamber are symmetrical in 0° and 180° angular positions of the rotor with respect to the axis connecting the angles 0°-180°.

[0057] In a preferred embodiment of the disclosure, the pumping device comprises two rotors, each running in a pumping chamber with a phase shift of 180° with respect to the angular position on their orbital paths, for an overall almost constant volume flow of the fluid at a common outlet.

[0058] In an advantageous embodiment of the disclosure, this is realized by the superposition of two approximately sinusoidal flow curves of the individual pump chamber rotor arrangements that are phase-shifted by 180°.

[0059] In a preferred embodiment of the disclosure, the rotors can be driven eccentrically on a common shaft, so that a very good mass balance and a virtually pulsation-free overall flow are possible.

[0060] The mass balance also reduces the vibrations of the pumping device.

[0061] A ventilation device according to the disclosure has at least one pumping device according to the above description for conveying the respiratory gas.

[0062] In a preferred embodiment of a device for ventilation according to the disclosure, said device comprises a pumping device with two rotors, each aligned offset by 180° with respect to their angular position, in a pumping chamber, with which a virtually pulsation-free course of the flow of the respiratory gas at a common outlet is realized.

[0063] In one embodiment of a device for ventilation according to the disclosure, the device further comprises a flow measuring device for measuring the volume flow of the respiratory gas.

[0064] In a preferred embodiment of a ventilation device according to the disclosure, the device comprises a control device for regulating the flow of the respiratory gas at the outlet of the pump device. In particular, the speed of the eccentric drive of the at least one rotor of the pump device can be controlled by means of a control unit.

[0065] The features of a method for providing breathing gas disclosed below are part of the invention both individually and in all executable combinations.

[0066] A method for providing breathing gas according to the disclosure comprises at least the following method steps: moving a rotor in a pumping chamber from a 0° angular position, in which the rotor has two points of contact with the inner wall of the pumping chamber and thereby seals the inlet and outlet areas from the rest of the pumping chamber (pressure chamber), in the direction of movement of the rotor on an orbital path into a position in which the rotor and the inner wall of the pumping chamber have exactly one point of contact, separating a pressure chamber in front of the rotor in the direction of movement and a suction chamber in the direction of movement behind the rotor by the point of contact between the rotor and the inner wall of the pumping chamber, sucking in breathing gas from the inlet into the suction chamber and conveying the breathing gas from the pressure chamber via the outlet by a continuous displacement of the rotor in the pumping chamber,whereby the same process steps are implemented with a second rotor in a second pumping chamber in a 180° phase-shifted sequence, so that when the rotors move around on the respective orbital paths within the respective pumping chamber at a constant running speed at a common outlet, a flow pattern of the breathing gas that is as smooth as possible is achieved.

[0067] In a preferred embodiment of the method according to the disclosure, the flow of the breathing gas is regulated by controlling the speed of movement of the runners.

[0068] In an advantageous embodiment of the method according to the disclosure, a pumping device according to the disclosure or a device for ventilation according to the disclosure comprising a pumping device according to the disclosure is used in accordance with the above description.

[0069] In advantageous embodiments, the invention has at least the following advantages and properties: A low (mass) inertia in the system for low-energy pressure / flow changes A low power requirement at constant pressure or flow The possibility of pressure and / or flow-controlled ventilation A compact design with low weight A feasible pressure increase of at least Δp = 60 hPa A feasible pressure increase of Δ̇ p = 180 hPa / s A peak flow of V = 180 V ˙ = 180 L min

[0070] The low rotational energy in the disclosed system enables a highly dynamic yet energy-efficient system. Ideally, the pressure can be maintained without moving the rotor(s). System cooling requirements are lower than with a fan, since the greatest energy requirement is for changing the rotational energy, which is lower in a disclosed system. In contrast to a fan, the flow of the outflowing fluid is less turbulent, which provides advantages for downstream flow measurement.

[0071] The design principle according to the invention described above can optionally also be applied to compressors or vacuum pumps.

[0072] The figures illustrate exemplary embodiments of the disclosure. They show: Figure 1: A cross-section of a pumping device according to the invention in the region of the pumping chamber in the 0° angular position of the rotor. Figure 2: A cross-section of a pumping device according to the invention in the region of the pumping chamber in the 60° angular position of the rotor. Figure 3: A cross-section of a pumping device according to the invention in the region of the pumping chamber in the 180° angular position of the rotor. Figure 4: A cross-section of a pumping device according to the invention in the region of the pumping chamber in the 300° angular position of the rotor. Figure 5: A diagram of the flow patterns of the fluid at the outlet of two pumping chambers and a common outlet of both pumping chambers. Figure 6: A perspective view of a cross-section of a pumping device according to the disclosure. Figure 7: A perspective view of a section in the longitudinal direction of a pumping device according to the invention with two pumping chambers and two rotors.Figure 8: A schematic representation of the cross section of a rotor of a device according to the disclosure, Figure 9: The radial course of the radius r of the rotor shown in the , Figure 8 illustrated rotor over the angle α, Figure 10: A schematic representation of the cross section of a rotor in a pump chamber of a device according to the disclosure, Figure 11: A cross section of a further embodiment of a pump device according to the disclosure and Figure 12: A flow diagram of a method according to the disclosure for providing breathing gas.

[0073] Figure 1shows a schematic representation of a section through an embodiment of a pumping device (1) according to the invention. The pumping device (1) has a pumping chamber (2) which is integrated into a housing (3). A rotor (4) is arranged in the pumping chamber (2). The rotor (4) has a rotor wall (4a), a rotor core (4b) and webs (4c) which connect the rotor core (4b) to the rotor wall (4a). This design makes it possible to make the rotor (4) hollow on the inside, so that the mass of the rotor (4) is low. The pumping chamber (2) has an inlet (5) and an outlet (6), wherein a fluid can flow into the pumping chamber (2) through the inlet (5) and out of the pumping chamber (2) through the outlet (6). The rotor (4) can be moved within the pumping chamber (2) by means of a drive (7). The drive (7) is preferably designed as an eccentric drive, so that the rotor (4) can be moved on an orbital path in the pump chamber (2).On the right-hand side, the rotor (4) has a separating element (8) designed as a connecting rod, which separates the inlet (5) area from the outlet (6). At its end facing away from the rest of the rotor (4), the separating element (8) has a sealing element (10) that is linearly guided in a guide (9). With the help of the sealing element (10), the inlet (5) area in the area of ​​the guide (9) is sealed off from the outlet (6). The arrow in the area of ​​the drive (7) indicates the angular position of the rotor (4), which here is the zero position. In the zero position or the 0° angular position, the rotor (4) has two points of contact (A, A') with the inner wall of the pump chamber (2).The pressure chamber (12) formed in this position in the pumping chamber (2) between the rotor wall (4a) and the inner wall of the pumping chamber (2) is separated from the outlet (6) by the first contact point (A) and from the inlet (5) by the second contact point (A').

[0074] The shapes of the rotor (4) and the pumping chamber (2) are coordinated such that the volume flow or flow of a fluid flowing out of the outlet (6) of the pumping device (1) is approximately sinusoidal at a constant speed of movement of the rotor (4). On the left side, the contour of the rotor wall (4a) corresponds approximately to the contour of an ellipse with a first diameter, and on the right side to two overlapping circles with a smaller diameter. The first circle merges into the two smaller circles.

[0075] In Figure 2 is the Figure 1The pumping device (1) shown is shown in an angular position of approximately 60°. The rotor (4) and the inner wall of the pumping chamber (2) only have one point of contact (A). A pressure chamber (12) is formed between the rotor (4) and the inner wall of the pumping chamber (2) upstream of the point of contact (A) in the direction of movement, which is defined by the clockwise direction, and a suction chamber (11) is formed downstream of the point of contact (A) in the direction of movement. As a result of the movement of the rotor (4) in the pumping chamber (2), a fluid can be sucked into the pumping chamber (2) via the inlet (5). The separating element (8) which is connected to the rotor (4) and designed as a connecting rod is slightly inclined according to the position of the rotor (4).

[0076] In Figure 3 is the one in the Figures 1 and 2The pumping device (1) shown is shown in the 180° angular position. In this position, the suction chamber (11) and the pressure chamber (12) are of equal size. The volume flow of a fluid flowing from the outlet (6) of the pumping device (1) reaches its maximum in this position.

[0077] In Figure 4 The pumping device (1) according to the disclosure shown in the previous figures is shown at an angular position of 300°. The suction chamber (11) now occupies the majority of the volume of the pumping chamber (2), while the pressure chamber (12) accounts for only a very small portion. The volume flow of a fluid flowing out of the pumping device (1) via the outlet (6) is already approaching its minimum.

[0078] The shape of the rotor (4) and the pumping chamber (2) are matched to one another in such a way that only in the 0° angular position on the orbital path of the rotor (4) are there two contact points (A, A') between the rotor wall (4a) and the inner wall of the pumping chamber (2), while in all other angular positions there is only one contact point (A).

[0079] In Figure 5The flow curve of a pump device (1) according to the disclosure, having two pump chambers (2), in each of which a rotor (4) is arranged, is shown, the rotors (4) being driven 180° out of phase with one another. The flow curve over the angular position corresponds approximately to a sine wave, with the minimum for each pump chamber (2) being 0% and the maximum being more than 95% of the total volume flow. Also shown is the cumulative flow curve (total volume flow) of a common outlet (6) to which both pump chambers (2) are connected. The total flow of the pump device (1) is almost constant and varies only between approximately 95% and 100%.

[0080] Figure 6shows a perspective view of a pump device (1) according to the disclosure, wherein a closure element sealing the pump chamber (2) upwards, such as a sealed closure cap, is not mounted, so that the pump chamber (2) is open. The rotor (4) is located approximately at a 180° angle.

[0081] One end of the shaft (13) of the drive (7) can be seen, to which a decoupling device (15) designed as a rolling bearing is connected via a connecting mechanism (20). The shaft (13) is arranged eccentrically within the decoupling device (15), thus creating an eccentric drive for the rotor (4). Also connected to the connecting mechanism (20) is a mass balancing element (16), which can be used to compensate for the uneven mass distribution that would otherwise cause an imbalance when the shaft (13) rotates. The rotor core (4b) is connected to the rotor wall (4a) via webs (4c). Ribs (4d) are arranged inside the rotor (4). Together with the mass balancing element (16), these ribs serve to shift the center of gravity of the rotor (4) to the center of the rolling bearing used and / or to the center of the motor axis or shaft (13). This largely avoids vibrations or at least suppresses them.At the end of the separating element (8) facing away from the rotor (4), a multi-part sealing element (10) is arranged, which has a resilient abutment (10a) and a roller (10b). This arrangement allows the separating element (8) to be pressed against the housing wall on the opposite side by the pressure at the outlet (6), so that the separating element (8) seals against the housing. The spring-loaded running surface or resilient abutment (10a) thus ensures a minimum contact pressure, and the outlet pressure provides additional support in case of doubt.

[0082] Figure 7shows a schematic representation of a section in the longitudinal direction through an embodiment of a pumping device (1) according to the invention having two pumping chambers (2', 2"), each with an associated rotor (4', 4"). The first rotor (4') is arranged in the first pumping chamber (2') and is located approximately at an angular position of 180°. The second rotor (4") is arranged in the second pumping chamber (2") and is located approximately at an angular position of 0°. The first pumping chamber (2') is separated from the second pumping chamber (2") by a partition wall (19). Furthermore, a motor (14) is arranged below the pumping chambers (2', 2"), with which a shaft (13) can be driven. The shaft (13) is used to drive both rotors (4', 4").A decoupling device (15) designed as a ball bearing is eccentrically connected to the shaft (13) in the area of ​​each pump chamber (2', 2") by means of a connecting mechanism (20), so that the rotors (4', 4") can move on orbital paths within the pump chambers (2', 2"). By aligning the rotors (4', 4") on the shaft (13), the phase offset between the rotors (4', 4") is fixed at 180°. By using a common shaft (13), a change in the phase offset during operation of the pump device (1) is excluded. The mass balancing elements (16', 16") are also arranged offset by 180° from one another.

[0083] The rotors (4', 4") each have a sliding ring (21) at their ends in the axial direction, which has an extension in the region of the separating element (8). The sliding rings (21) are each inserted into a circumferential groove, whereby the sliding rings (21) are not completely countersunk into the groove. The sliding rings (21) run along the walls that bound the pump chambers (2', 2") in the axial direction and thereby seal the pump chamber (2', 2") from the interior of the respective rotor (4', 4"). To improve the sealing effect, even with increased component tolerances, the sliding rings (21) are spring-loaded with spring elements (22) such that they are pressed against the housing wall. In the embodiment shown in the disclosure, the spring elements (22) are located behind the sliding rings (21) in the respective groove. The shaft (13) is sealed by means of a shaft seal (23).

[0084] In other embodiments of the disclosure, other positions of the motor (14) of the drive are also conceivable, for example between the pump chambers (2°, 2").

[0085] In Figure 8 A schematic representation of the cross-section of a rotor (4) of a device (1) according to the disclosure is shown. The shape of the rotor (4) is defined by a spline function. Furthermore, the radius r and the angle α are specified, with which the shape of the rotor (4) can be described in the illustrated coordinate system with the X-axis and Y-axis.

[0086] Figure 9 shows the course of the radius r over the angle α of the Figure 8 depicted runner.

[0087] The triangles indicate the values ​​(radius versus angle) defined for the spline function (handles). The curve is a cubic spline function in the Cartesian coordinate system, which is translated into the polar coordinate system.

[0088] The curve is not symmetrical to the 180° center. This means that the rotor (4) of the corresponding embodiment of a device according to the invention is also not symmetrical to the x-axis. By optimizing the shape, it is designed so that the flow of the outflowing fluid is as constant as possible.

[0089] In Figure 10 A schematic representation of a cross-section of a rotor (4) shaped according to a spline function in a correspondingly designed pumping chamber (2) is shown. The contour of the pumping chamber (2) is determined by the envelope of the rotor shape, which is shifted over a complete revolution (0° - 360°) via the crank angle according to the eccentric drive.

[0090] The circle shown inside the rotor (4) is the circle of the eccentric center point.

[0091] Figure 11shows a cross section of an embodiment of a pump device (1) according to the disclosure with a housing (3) of the pump chamber (2), which is designed to be resilient relative to the rotor (4).

[0092] For this purpose, the housing (3) has lamellae (24) on its inside that project into the pump chamber (2).

[0093] In the illustrated embodiment, the lamellae (24) are slightly inclined in the direction of movement of the rotor (4). This ensures a low frictional force counteracting the movement of the rotor (4) while simultaneously providing a good sealing effect.

[0094] In such an embodiment of the invention, depending on the angular position of the rotor (4) in the pump chamber, there is no longer exactly one contact point (A) or there are no longer exactly two contact points, but rather a contact area around this point or these points in which the rotor (4) is contacted by a plurality of lamellae (24).

[0095] Furthermore, the illustrated embodiment of a pumping device (1) according to the invention has a modification of the sealing element (10) that can also be implemented for all other embodiments shown, which sealing element connects the separating element (8) on its side facing away from the rotor (4) to the housing (3) of the pumping chamber (2) in a sealing manner. The sealing element (10) has a lever (10c) that is mounted on the housing (3) for rotation about a first axis of rotation and is connected to the end of the separating element (8) for rotation about a second axis of rotation, so that, in contrast to the embodiment as a connecting rod sealingly mounted in a guide (9), less friction occurs in this area.

[0096] In Figure 12The sequence of a method for providing breathing gas according to the disclosure is schematically illustrated. When using a pump device according to the invention with a housing that is resilient relative to the rotor, contact areas extending around the rotor and housing are provided instead of the contact point(s).

Claims

1. Respiratory device comprising at least one pump device (1), wherein the pump device (1) has at least one pump chamber (2) and a rotor (4) arranged in the pump chamber (2) for each pump chamber (2), wherein the at least one pump chamber (2) has an inlet (5) and an outlet (6), wherein a fluid can flow into the pump chamber (2) via the inlet (5) and out of the pump chamber (2) via the outlet (6), wherein the inlet (5) and the outlet (6) are connected to the pump chamber (2) via a common channel and wherein the inlet (5) is separated from the outlet by a separating element (8) arranged in the channel and wherein the rotor (4) can be driven on an orbital path within the pump chamber (2) and the shape of the rotor (4) and the shape of the pump chamber (2) are designed and matched to one another, that by the movement of the rotor (4) in the pump chamber (2) at a constant speed an approximately sinusoidal course of the flow of the fluid flowing out of the outlet (6) is realized, wherein this has two pump chambers (2', 2") and per pump chamber (2', 2") a rotor (4', 4") is arranged in the pump chamber (2', 2"), wherein the rotors (4', 4") are arranged in the pump chambers (2', 2") 180° out of phase with one another, characterized in that the pump chambers (2', 2") have a common outlet (6), so that the approximately sinusoidal flows which can be generated with the aid of the two pump chambers (2', 2") and rotors (4', 4") in each case produce a cumulative, virtually constant total volumetric flow.

2. Respiratory device according to claim 1, characterized in that the rotor (4) is movable on the orbital path by means of an eccentric drive.

3. Respiratory device according to one of the preceding claims, characterized in that the shape of the rotor (4) and the shape of the pump chamber (2) are designed and matched to one another in such a way that, when the cross-section is viewed in the 0° angular position of the rotor (4) inside the pump chamber (2), two points of contact (A, A') or two contact areas arranged around these contact points (A, A') are realized between the rotor (4) and the inner wall of the pump chamber (4) and in all other angular positions only one contact point (A) or one contact area arranged around this contact point (A) is realized between the rotor (4) and the inner wall of the pump chamber (4).

4. Respiratory device according to one of the preceding claims, characterized in that the separating element (8) is connected to the rotor (4) and projects from the latter into the region of the inlet (5) and the outlet (6).

5. Respiratory device according to one of the preceding claims, characterized in that the rotor (4) is resiliently mounted relative to the housing (3) of the pump chamber (2).

6. Respiratory device according to one of the preceding claims, characterized in that the housing (3) of the pump chamber (2) is designed to be resilient with respect to the rotor (4).

7. Respiratory device according to claim 6, characterized in that the housing (3) of the pump chamber (2) has lamellae (24) projecting inwards into the pump chamber (2) and extending transversely to the direction of movement of the rotor (4).

8. Respiratory device according to one of the preceding claims, characterized in that the shape of the rotor (4) is designed in cross-section corresponding to a spline function generated in cartesian coordinates and transferred to polar coordinates, so that a curve progression without jumps is made possible.

9. Respiratory device according to one of claims 1 to 8, characterized in that the rotors (4', 4") can be driven by means of a common shaft (13).

10. Respiratory device according to claim 8, characterized in that the spline function is formed from cubic parabolas.

11. Method for providing a respiratory gas, comprising the method steps of displacing a rotor in a pump chamber from a 0° angular position, in which the rotor has two contact points (A, A') or two contact regions arranged around these contact points (A. A') with the inner wall of the pump chamber and thereby seals the inlet and outlet areas from the rest of the pump chamber, in the direction of movement of the rotor on an orbital path to a position in which the rotor and the inner wall of the pump chamber have exactly one point of contact (A) or a point of contact (A') arranged around these points of contact (A. A'). an area of contact arranged around this point of contact (A), separating a pressure chamber in the direction of movement in front of the rotor and a suction chamber in the direction of movement behind the rotor by the point of contact of the rotor and the inner wall of the pump chamber, drawing in breathing gas from the inlet into the suction chamber and conveying the breathing gas from the pressure chamber via the outlet by a continuous displacement of the rotor in the pump chamber, wherein the same process steps are implemented in a 180° phase-shifted sequence with a second rotor in a second pump chamber, so that with a movement of the rotors rotating on the respective orbital paths within the respective pump chamber at a constant running speed at a common outlet, a flow course of the respiratory gas which is as jump-free as possible is realized, characterized in that a respiratory device according to one of claims 1 to 10 is used.