Pump device, breathing device and method for providing breathing gas

Abstract

The invention relates to a pump device, a breathing device and a method for providing breathing gases. The solution of the invention teaches the use of a specially shaped rotor and a corresponding pump chamber, thereby enabling a substantially sinusoidal flow of the outflowing fluid. When the two pump chambers of the invention are combined with rotors driven with a phase offset of 180°, an almost constant flow can be achieved at the common outlet. In addition, the system of the invention is designed for high dynamics with a relatively low energy consumption.

Description

Technical Field

[0001] The invention relates to a pump device in the sense of a positive displacement pump, in particular designed for conveying gases.

[0002] Furthermore, the invention relates to a breathing device having such a pump device.

[0003] Furthermore, the invention relates to a method for providing breathing gas by means of a breathing device. Background Art

[0004] When a patient is mechanically ventilated using a breathing apparatus, there are special requirements for effective ventilation.

[0005] In extreme respiratory situations, for example, at a minute flow rate of and maximum pressure increase

[0006] When Δp = 60hPa, the average aerodynamic power is This means that the pneumatic power requirement is lower. This requirement is exacerbated by intermittent operation, in which short suctions are accompanied by

[0007] Rapid pressure increase and high flow rates (volume flow). The necessary peak

[0008] Flow and up to Although the pressure increase requires higher peak aerodynamic power, the average aerodynamic power remains in the low range of a few watts.

[0009] Known breathing devices usually have a blower to generate the required flow and pressure, which sucks air through an inlet and delivers air through an outlet by means of a fan impeller rotating in a housing. This blower has various advantages, such as compact and simple structure, high flow power and high dynamics, and is therefore almost an ideal pressure source. However, a large speed stroke is required to build up pressure, the applicability as a flow source is quite low, the strong turbulence of the leakage fluid makes downstream flow measurement difficult, and the average pneumatic total efficiency is significantly lower than 10%. In detail, the rapid speed increase accompanied by the pressure increase leads to a significant change in the rotational energy stored in the fan impeller, which requires high power. These required powers are in the range of more than 40W and are significantly higher when the required pressure increase is very fast. In addition, there is a high static power demand at high speeds. In general, when a blower is used in a breathing device, a large amount of heat is generated, which must be dissipated, so cooling measures are essential.

[0010] As an alternative to blowers, the prior art includes, in particular, piston pumps and diaphragm pumps for use in breathing apparatus, which partially reduce the turbulence of the outflowing fluid and reduce heat losses, but due to their design they place particularly high demands on component tolerances, thereby increasing the production costs for correspondingly precisely dimensioning the components. Summary of the invention

[0011] The object of the present invention is to provide a pump device which has improved performance in terms of power consumption and heat dissipation compared to a blower.

[0012] According to the invention, this object is achieved by the pump device according to the invention.

[0013] Another object of the invention is to provide a pump device which, compared with a blower, enables a less turbulent flow of the discharged fluid.

[0014] According to the invention, this object is achieved by the pump device according to the invention.

[0015] Another object of the invention is to provide a pump device which places lower demands on component tolerances.

[0016] According to the invention, this object is achieved by the pump device according to the invention.

[0017] Another object of the present invention is to provide an improved breathing apparatus.

[0018] According to the invention, this object is achieved by the breathing device according to the invention.

[0019] Another object of the present invention is to provide an improved method for providing breathing gas.

[0020] According to the invention, this object is achieved by the method according to the invention for providing breathing gas.

[0021] The advantageous features of the invention are given in the technical solution of the invention.

[0022] The features of the pump device disclosed below form part of the invention both individually and in all practicable combinations.

[0023] The pump device according to the invention is designed as a positive displacement pump or displacement pump and has at least one pump chamber and each pump chamber has a rotor arranged in the pump chamber.

[0024] The pump chamber is arranged in the housing and is designed as a stator of the pump device.

[0025] The pump chamber has an inlet and an outlet through which fluid flows into or out of the pump chamber.

[0026] The rotor is movable in the pump chamber while being guided along the pump chamber wall.

[0027] In one embodiment of the invention, the rotor moves non-rotatably within the pump chamber in the sense that, although the position of the rotor within the pump chamber is changeable, its orientation is not changeable.

[0028] In one embodiment of the invention, the rotor or a point of the rotor on the track can be moved in a guided manner.

[0029] In one embodiment of the invention, the rotor is eccentrically mounted on a rotatable shaft of the drive device and is decoupled from the rotation by a decoupling device, so that an orbital motion of the rotor can be achieved.

[0030] In one embodiment of the invention, the decoupling device is designed as a rolling bearing.

[0031] The rotor can move in the pump chamber, so that a suction space can be formed behind the rotor in the pump chamber along the direction of movement, and the fluid can be sucked into the suction space through the inlet by the movement of the rotor. A pressure chamber can be formed in the pump chamber in front of the rotor along the direction of movement, and the fluid can be discharged from the pressure chamber through the outlet of the pump chamber by the movement of the rotor.

[0032] Here, depending on the angular position of the rotor in the pump chamber, the suction chamber is defined as the volume of the pump chamber connected to the inlet minus the volume of the rotor, and the pressure chamber is defined as the volume of the pump chamber not connected to the inlet minus the volume of the rotor.

[0033] In one embodiment of the invention, the inlet and the outlet of the pump chamber are arranged on a common channel connected to the pump chamber. The channel is divided into an area assigned to the inlet and an area assigned to the outlet by a partition element.

[0034] In one embodiment of the invention, the separation element is connected to the rotor.

[0035] In one embodiment of the invention, the separating element is designed as a connecting rod which is shaped at least in regions in a rod-like manner and is connected to the rotor.

[0036] In a preferred embodiment of the invention, a connecting rod connected to the rotor projects from the pump chamber into the pump chamber inlet region and outlet region and seals the inlet relative to the outlet.

[0037] In one embodiment of the invention, the connecting rods of the rotor are linearly guided at the end facing the rest of the rotor.

[0038] In one embodiment of the invention, the stator, in particular the wall of the pump chamber, is made of metal, thereby providing a high dimensional stability and thermal conductivity.

[0039] In a preferred embodiment of the invention, the wall of the pump chamber is formed from aluminum, which, in addition to high dimensional stability and thermal conductivity, has a relatively low mass.

[0040] In one embodiment of the invention, the rotor is formed from a sliding plastic, thereby achieving low friction between the rotor and the inner wall of the pump chamber.

[0041] In this case, the flow curve of the fluid exiting from the outlet of the pump chamber is directly coupled to the volume curve of the suction chamber or pressure chamber, depending on the angular position of the rotor in the pump chamber.

[0042] In a preferred embodiment of the invention, the rotor has at least one cavity for reducing the mass of the rotor. The lower the mass of the rotor, the lower the energy required to adjust the operating speed of the rotor.

[0043] In a preferred embodiment of the present invention, the rotor is designed relative to the inner wall of the pump chamber so that it has two contact points with the inner wall of the pump chamber in the cross section at exactly one position on the orbital motion trajectory of the rotor achieved by means of the eccentric drive device, while the rotor has only one contact point with the inner wall of the pump chamber in the cross section at all other positions.

[0044] Depending on the three-dimensional design of the rotor and the pump chamber, generally one contact line or two contact lines are realized depending on the position of the rotor. In a disk-shaped structure in which the rotor and the pump chamber each extend over a height h with a surface of constant shape, the contact line is a straight line or a straight line segment.

[0045] In a preferred embodiment of the invention, the separation element is arranged in the circumferential direction of the rotor between two contact points of the rotor and the inner wall of the pump chamber, wherein a small distance between the contact points in the circumferential direction is decisive.

[0046] In a particularly preferred embodiment of the invention, in a position where the rotor has two contact points with the inner wall of the pump chamber, both the path from the inlet to the residual volume of the pump chamber and the path from the outlet to the residual volume of the pump chamber are blocked, so that the volume in the pump chamber is closed.

[0047] The position where the rotor and the inner wall of the pump chamber have two contact points is defined as the zero position or 0° angular position relative to the trajectory of the orbital motion. The angle increases depending on the position of the rotor in its direction of motion until the zero position is reached again at an angular position of 360°.

[0048] In one embodiment of the invention, 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 pump chamber, thereby improving the seal at at least one contact point between the rotor and the inner wall of the pump chamber. This can in particular improve manufacturing tolerances.

[0049] In a further embodiment of the invention, the housing wall is designed in such a way that it is designed to be elastic relative to the rigidly mounted rotor, so that in particular higher production tolerances can be achieved.

[0050] In one embodiment of the invention, the housing wall of the pump chamber is formed slightly smaller than the ideal contour of the corresponding rotor and can be pressed slightly outwards by the rotor at this contact point / points.

[0051] In another embodiment of the invention, the housing of the pump chamber has fins protruding inwardly into the pump chamber, which extend transversely to the direction of movement of the rotor in the pump chamber and contact the rotor in the region of this contact point or these contact points. The pressure generated in the pump chamber presses the fins onto the rotor, wherein the pressure of the fins is very low, without a significant initial pressure or output pressure.

[0052] In a further embodiment of the invention, one of the above-described embodiments of the rotor and the pump chamber housing is combined with one another.

[0053] In a preferred embodiment of the invention, the shapes of the pump chamber and the rotor are matched to one another so that, at a constant speed of the rotor, a non-step profile of the flow of the delivered fluid is achieved at the outlet of the pump chamber.

[0054] In a preferred embodiment of the present invention, the shapes of the pump chamber and the rotor are matched so that at a constant speed of the rotor, an approximately sinusoidal variation curve of the delivered fluid is achieved at the outlet of the pump chamber, wherein the minimum value of the flow is approximately 0 (no flow in the opposite direction).

[0055] In one embodiment of the present invention, the rotor is circular. However, due to the thickness of the partition wall between the inlet and the outlet (in the embodiment of the present invention, the partition element is realized by a connecting rod), the flow curve of the fluid at the outlet is slightly deviated from the sine curve.

[0056] The thinner the rod of the partition element or connecting rod is, the closer the flow curve of the fluid at the outlet is to a sinusoidal shape. In an embodiment of the present invention, the partition element or connecting rod is therefore not rigid, but is constructed as a thin partition layer, which connects the inlet and outlet to the housing of the pump device in a sealed manner at the end facing away from the rotor.

[0057] In this case, the separating element or connecting rod and / or the sealing connection of the separating element or connecting rod to the housing is designed to be flexible, so that the movement of the rotor on the track is not disrupted.

[0058] The volume that can be delivered in a rotor cycle using a pump device depends on the eccentricity of the rotor, with the pumping volume increasing with increasing eccentricity. This is because the path of the rotor is lengthened with increasing eccentricity, so the size of the pumping chamber must be adjusted accordingly.

[0059] A disadvantage of a circular rotor is that for a sinusoidal flow curve of the fluid out of the outlet, only a small eccentricity is possible and therefore only a small pumping volume can be achieved. To solve these problems, in a preferred embodiment of the invention the shape of the rotor is adapted to be away from a circle.

[0060] In a preferred embodiment of the invention, the rotor has a circular basic shape which is expanded by a circle which is arranged laterally adjacent to the separation element and partially protrudes beyond the circular basic shape of the rotor and has a smaller diameter than the circular basic shape. The transition between the basic shape and the smaller circle takes place smoothly at least on the side facing away from the separation element.

[0061] In a further embodiment of the invention, the rotor according to the preceding embodiment has an elliptical basic shape instead of a circle, wherein the half of the ellipse facing the separating element is modified by two overlapping circles in certain areas and the transition from the ellipse to the circle is designed to be smooth.

[0062] In another embodiment of the invention, the shape of the rotor is formed according to a spline function.

[0063] Spline functions are advantageously used for shaping rotors because they enable a curve with no jumps. By generating the spline function in Cartesian coordinates and converting it into polar coordinates (radius and angle), any number of rotor curves with no jumps can be generated, which can be further optimized with regard to the flow profile.

[0064] In one embodiment of the invention, the approximately sinusoidal curve of the outflowing fluid is achieved by an approximately sinusoidal free cross section in the region of the outlet or in the region of the connection of the outlet to the pump chamber, which is connected to the pump chamber during the circulation of the rotor in the pump chamber.

[0065] In a preferred embodiment of the invention, the shape of the rotor and the shape of the pump chamber are symmetrical in the angular positions of the rotor 0° and 180° about an axis connecting these angles 0°-180°.

[0066] In a preferred embodiment of the invention, the pump device comprises, in each pump chamber for an overall virtually constant fluid volume flow at a common outlet, two rotors which run on their paths with a phase shift of 180° with respect to the angular position.

[0067] In an advantageous embodiment of the invention, this is achieved by superimposing two approximately sinusoidal flow curves of a single pump chamber / rotor assembly which are phase-shifted by 180°.

[0068] In a preferred embodiment of the invention, the rotors are driven eccentrically on a common shaft, so that very good mass compensation and a virtually pulsation-free overall flow can be achieved.

[0069] The mass compensation also reduces vibrations of the pump arrangement.

[0070] The breathing device according to the invention has at least one pump device according to the above description for conveying breathing gas.

[0071] In a preferred embodiment of the breathing device according to the invention, the device comprises a pump device which has two rotors in each pump chamber which are oriented 180° offset with respect to their angular position and by which a virtually pulsation-free flow profile of the breathing gas at the common outlet is achieved.

[0072] In one embodiment of the breathing device according to the invention, it further comprises a flow measuring device for measuring the volume flow of the breathing gas. In a preferred embodiment of the breathing device according to the invention, it further comprises a control device for regulating the flow of the breathing gas at the outlet of the pump device. For this purpose, in particular the rotational speed of the eccentric drive of at least one rotor of the pump device can be controlled by the control unit.

[0073] The features disclosed below of the method for providing breathing gas form part of the present invention both individually and in any practicable combination.

[0074] The method for providing breathing gas of the present invention comprises at least the following method steps:

[0075] The rotor is moved in the pump chamber from an angular position of 0° (in which the rotor has two contact points with the inner wall of the pump chamber when observing the cross section and thus the inlet area and the outlet area are sealed relative to the rest of the pump chamber (pressure chamber)) along the movement direction of the rotor on the operating trajectory to a position (in which the rotor and the inner wall of the pump chamber have exactly one contact point); the pressure chamber in front of the rotor in the movement direction is separated from the suction chamber behind the rotor in the movement direction by the contact point between the rotor and the inner wall of the pump chamber; breathing gas is sucked into the suction chamber from the inlet and discharged from the pressure chamber through the outlet by the continuous movement of the rotor in the pump chamber, wherein the second rotor in the second pump chamber implements the same method steps with a phase offset of 180°, thereby achieving a flow curve of the breathing gas that is as free of jumps as possible at the common outlet when the rotor rotates on the corresponding track at a constant operating speed in the respective pump chambers.

[0076] In a preferred embodiment of the method of the invention, the flow of the breathing gas is regulated by controlling the movement speed of the rotor.

[0077] In an advantageous embodiment of the method according to the invention, a pump device according to the invention or a breathing device according to the invention having a pump device according to the above description is used.

[0078] In an advantageous embodiment, the present invention has at least the following advantages and features:

[0079] Low inertia in the system for low energy pressure / flow changes

[0080] Low power consumption at constant pressure or flow

[0081] Possibility of pressure- and / or flow-controlled breathing

[0082] Compact design and light weight

[0083] A pressure increase of at least Δp = 60 hPa can be achieved

[0084] Achievable Increased pressure

[0085] Peak flow

[0086] The low rotational energy in the system according to the invention makes it possible to achieve a highly dynamic and at the same time energy-saving system. Ideally, the pressure can be maintained without movement of the rotor or rotors. The requirements for system cooling are lower than with a blower, since the maximum energy is required to change the rotational energy, which is lower in the system according to the invention. Unlike a blower, the flow turbulence of the outflowing fluid is less, which offers advantages for flow measurement downstream.

[0087] The design principles of the present invention described above may also be optionally applied to a compressor or a vacuum pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In the accompanying drawings, exemplary embodiments of the present invention are shown. In the accompanying drawings:

[0089] Figure 1 : shows a cross section of the pump device according to the invention in the pump chamber region at an angular position of the rotor of 0°,

[0090] Figure 2 : shows a cross section of the pump device of the present invention in the pump chamber region at an angular position of the rotor of 60°,

[0091] Figure 3 : shows a cross section of the pump device according to the invention in the pump chamber region at an angular position of 180° of the rotor,

[0092] Figure 4 : shows a cross section of the pump device according to the invention in the pump chamber region at an angular position of the rotor of 300°,

[0093] Figure 5 : A flow curve diagram showing the outlets of the two pump chambers and the common outlet of the two pump chambers,

[0094] Figure 6 : A perspective view showing a cross section of a pump device according to the invention,

[0095] Figure 7 : A perspective view showing a section in the longitudinal direction of a pump device according to the invention having two pump chambers and two rotors,

[0096] Figure 8 : A schematic cross-sectional view showing a rotor of the device of the present invention,

[0097] Fig. 9 : Show Figure 8 The radial trajectory of the rotor radius r at the angle α is shown,

[0098] Fig.10 : A schematic cross-sectional view showing a rotor in a pump chamber of a device according to the present invention,

[0099] Fig.11 : A cross-sectional view showing another embodiment of a pump device according to the present invention,

[0100] Fig.12 : A flow chart showing the method for providing breathing gas of the present invention. DETAILED DESCRIPTION

[0101] Figure 1A schematic diagram shows a cross section of a pump device (1) according to an embodiment of the present invention. The pump device (1) has a pump chamber (2) integrated in a housing (3). A rotor (4) is arranged in the pump chamber (2). The rotor (4) has a rotor wall (4a), a rotor core (4b) and a sheet (4c) connecting the rotor core (4c) to the rotor wall (4a). This structural method allows the rotor (4) to be hollow inside, so that the mass of the rotor (4) is small. The pump chamber (2) has an inlet (5) and an outlet (6), wherein a fluid can flow into the pump chamber (2) through the inlet (5) and flow out of the pump chamber (2) through the outlet (6). The rotor (4) can move in the pump chamber (2) via a drive device (7). The drive device (7) is preferably designed as an eccentric drive device, so that the rotor (4) can move on a track in the pump chamber (2). On the right side, the rotor (4) has a partition element (8) configured as a connecting rod, by which the area of ​​the inlet (5) is separated from the area of ​​the outlet (6). The separating element (8) has a sealing element (10) at its end facing away from the rest of the rotor (4), which is linearly guided in a guide (9). The region of the inlet (5) is sealed from the region of the outlet (6) in the region of the guide (9) by means of the sealing element (10). The angular position of the rotor (4) is indicated by an arrow in the region of the drive (7), which is indicated here by the zero position. In the zero position. In the zero position or 0° angular position, the rotor (4) has two contact points (A, A') with the inner wall of the pump chamber (2). In this position, the pressure chamber (12) formed in the pump chamber (2) between the rotor wall (4a) and the inner wall of the pump chamber (2) is separated from the outlet (6) by a first contact point (A) and separated from the inlet (5) by a second contact point (A').

[0102] The shapes of the rotor (4) and the pump chamber (2) are coordinated with each other so that the volume flow or the flow curve of the fluid flowing out of the outlet (6) of the pump device (1) is approximately a sine curve when the rotor (4) moves at a constant speed. 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 approximately to two overlapping circles with smaller diameters. In this case, the first circle merges into the two smaller circles.

[0103] exist Figure 2 Shown in Figure 1The pump device (1) shown in the drawing is in an angular position of approximately 60°. The rotor (4) and the inner wall of the pump chamber (2) have only one contact point (A). In the direction of movement given by clockwise rotation, a pressure chamber (12) is formed in front of the contact point (A) between the rotor (4) and the inner wall of the pump chamber (2), and a suction chamber (11) is formed behind the contact point (A) in the direction of movement. Through the movement of the rotor (4) in the pump chamber (2), the fluid can be sucked into the pump chamber (2) via the inlet (5). The partition element connected to the rotor (4) and configured as a connecting rod (8) is slightly tilted depending on the position of the rotor (4).

[0104] exist Figure 3 Shown in Figure 1 and Figure 2 The pump device (1) shown in the figure is in an angular position of 180°. In this position, the suction chamber (11) and the pressure chamber (12) are of equal size. The volume flow of the fluid flowing out of the outlet (6) of the pump device (1) reaches its maximum value in this position.

[0105] exist Figure 4 The pump device (1) according to the invention shown in the previous figures is shown in an angular position of 300°. The suction chamber (11) now occupies the majority of the volume of the pump chamber (2), while the pressure chamber (12) occupies only a very small proportion. The volume flow of the fluid flowing out of the pump device (1) via the outlet (6) is already close to a minimum value.

[0106] The shapes of the rotor (4) and the pump chamber (2) are coordinated with each other so that only in the 0° angular position on the running path of the rotor (4) are two contact points (a, a') provided between the rotor wall (4a) and the inner wall of the pump chamber (2), while in all other angular positions only one contact point is provided.

[0107] exist Figure 5 The flow curve of a pump device (1) according to the invention with two pump chambers (2) is shown, in each pump chamber a rotor (4) is arranged, wherein the rotors (3) are driven with a phase offset of 180° relative to one another. The flow curve at this angular position corresponds approximately to a sine, wherein for each pump chamber (2) there is a minimum at 0% and a maximum above 95% of the total volume flow. Also shown is the cumulative flow curve (total volume flow) of a common outlet (6) to which the two pump chambers (2) are connected. The total flow of the pump device (1) is almost constant and varies only between approximately 95% and 100%.

[0108] Figure 6 A perspective view of a pump device (1) according to the invention is shown, wherein a closure element, such as a sealed closure cover, which seals the pump chamber (2) upward is not installed, so that the pump chamber (1) is open. The rotor (4) is approximately in an angular position of 180°.

[0109] From the drive device (7) one end of the shaft (13) can be seen, to which a decoupling device in the form of a rolling bearing (15) is connected via a connecting means (20). The shaft (13) is arranged eccentrically inside the decoupling device (15), so that an eccentric drive of the rotor (4) is achieved. Furthermore, a mass compensation element (16) is connected to the connecting means (20), by means of which an uneven mass distribution can be compensated, which would otherwise lead to an imbalance when the shaft (13) rotates. The rotor core (4b) is connected to the rotor wall (4a) via a sheet (4c). Ribs (4d) are arranged inside the rotor (4), which together with the mass compensation element (16) serve to adjust the center of gravity of the rotor (4) to the center of the rolling bearing used and / or the center of the motor shaft or shaft (13). Vibrations are thereby avoided as much as possible or at least strongly suppressed. A multi-part sealing element (10) having an elastic bearing (10a) and a roller (10b) is arranged at the end of the separating element (8) facing away from the rotor (4). By means of this arrangement, the partition element (8) can be pressed against the housing wall on the opposite side by the pressure at the outlet (6) in uncertain situations, so that the partition element (6) is sealed relative to the housing. The spring-loaded working surface or elastic bearing (10a) thus ensures a minimum contact pressure, and the initial pressure also contributes to this in uncertain situations.

[0110] Figure 7 A schematic diagram shows a longitudinal section of a pump device (1) according to an embodiment of the invention, which has two pump chambers (2', 2"), each of which has an assigned rotor (4', 4"). The first rotor (4') is arranged in the first pump chamber (2') and is approximately in an angular position of 180°. The second rotor (4") is arranged in the second pump chamber (2") and is approximately in an angular position of 0°. The first pump chamber (2') is separated from the second pump chamber (1') by a partition wall (19). In addition, a motor (14) is arranged below the pump chamber (2', 2"), by which a shaft (13) can be driven. The shaft (13) is used to drive the two rotors (4', 4"). A decoupling device (15) configured as a ball bearing is eccentrically connected to the shaft (13) via a connecting mechanism (20) in each case in the area of ​​the pump chamber (2', 2"), so that the rotors (4', 4") can move on tracks inside the pump chamber (2', 2") . By orienting the rotors (4', 4") on the shaft (13), the phase offset between the rotors (4', 4') is fixedly set to 180°. In this case, the use of a common shaft (13) eliminates changes in the phase offset during operation of the pump device (1). The mass balancing elements (16', 16") are also arranged to be offset by 180° from each other.

[0111] The rotors (4', 4") each have a sliding ring (21) at their axial ends, which has an extension in the area of ​​the partition element (8). The sliding rings (21) are inserted into circumferential grooves, wherein the sliding rings (22) are not completely sunken into the grooves. The sliding rings (21) run on walls that axially delimit the pump chambers (2', 2") and seal the pump chambers (1', 2') relative to the interior of the respective rotor (4', 4'). In order to improve the sealing effect even in the case of increased component tolerances, the sliding rings (21) are loaded by spring elements (22) so that they are pressed against the housing wall. In the embodiment of the invention shown, the spring elements (22) are located behind the sliding rings (21) in the respective grooves. The shaft (13) is sealed by means of a shaft seal (23).

[0112] In other embodiments of the invention, other positions of the motor (14) of the drive device are also conceivable, for example between the pump chambers (2', 2').

[0113] exist Figure 8 A schematic cross-sectional view of a rotor (4) of the device (1) of the present invention is shown in FIG. The shape of the rotor (4) is defined by a spline function. In addition, a radius r and an angle α are given, by which the shape of the rotor (4) can be described in the X-axis and Y-axis coordinate system shown.

[0114] Fig. 9 The radius r is shown in Figure 8 The curve of the variation of the angle α of the rotor is shown. The triangles show for which values ​​of the spline function (radius with respect to the angle) have been determined (drag points). The curve is a cubic spline function in Cartesian coordinates, which is transformed into polar coordinates.

[0115] This curve is not symmetrical about the 180° center. That is, the rotor (4) of the corresponding embodiment of the device of the present invention is also not symmetrical about the x-axis. By optimizing the shape, it is designed to make the flow rate of the outflowing fluid as constant as possible.

[0116] exist Fig.10 Schematic diagram of a rotor cross section shaped according to a spline function (4) in a correspondingly formed pump chamber (2) is shown. The contour of the pump chamber (2) is derived from the envelope end of the rotor shape, which moves over the crank angle during the entire rotation (0°-360°) due to the eccentric drive.

[0117] The circle shown inside the rotor (4) is the circle of the eccentric point.

[0118] Fig.11 A cross section through an embodiment of a pump device (1) according to the invention is shown, which has a housing (3) of a pump chamber (2) which is designed to be elastic relative to a rotor (4).

[0119] For this purpose, the housing (3) has fins (24) on its inner side which protrude into the pump chamber (2).

[0120] In the embodiment shown, the fins (24) are arranged slightly inclined in the direction of movement of the rotor (4), thereby achieving low friction forces that counteract the movement of the rotor (4) while having a good sealing effect.

[0121] In this embodiment of the invention, depending on the angular position of the rotor (4) in the pump chamber, no longer just one contact point (A) or no longer just two contact points are achieved, but rather a contact range around this point or around these points, in which the rotor (4) is contacted by a plurality of fins (24).

[0122] The illustrated embodiment of the pump device (1) according to the invention also has a variant of the sealing element (10) which is realizable for all other embodiments and which seals the partition element (8) on its side facing away from the rotor (4) to the housing (3) of the pump chamber (2). The sealing element (10) has a rod (10c) which is mounted on the housing (3) so as to be rotatable about a first rotation axis and which is connected to the end of the partition element (8) so as to be rotatable about a second rotation axis, thereby generating lower friction in this area compared to the design of a connecting rod which is mounted sealingly in a guide (9).

[0123] exist Fig.12 The sequence of the method according to the invention for providing breathing gas is schematically shown in . When using a pump device according to the invention with a housing that is elastic relative to the rotor, a contact area extending around the contact point or points is realized between the rotor and the housing instead of the contact point or points.

Claims

1. A breathing device, comprising at least one pump device (1), the pump device having at least one pump chamber (2) and each pump chamber (2) having a rotor (4) arranged in the pump chamber (2), the at least one pump chamber (2) having an inlet (5) and an outlet (6), wherein a fluid can flow into the pump chamber (2) through the inlet (5) and can flow out of the pump chamber (2) through the outlet (6), wherein: The inlet (5) and the outlet (6) are connected to the pump chamber (2) via a common channel, wherein the inlet (5) is separated from the outlet by a partition element (8) arranged in the channel, and the rotor (4) can be driven on a track inside the pump chamber (2), and the shape of the rotor (4) and the shape of the pump chamber (2) are constructed and coordinated with each other so that the movement of the rotor (4) at a constant speed in the pump chamber (2) realizes a substantially sinusoidal curve of the flow rate of the fluid flowing out of the outlet (6) changing with time , wherein the pump device has two pump chambers (2', 2") and each pump chamber (2', 2") has a rotor (4', 4") arranged in the pump chamber (2', 2"), wherein the rotors (4', 4") are arranged in the pump chamber (2', 2") with a phase offset of 180° with respect to each other, wherein the two pump chambers (2', 2") have a common outlet (6), so that a cumulative, almost constant total volume flow is generated by means of the approximately sinusoidal flow rates generated by the two pump chambers (2', 2") and the rotors (4', 4"), respectively.

2. The breathing apparatus according to claim 1, characterized in that The rotor (4) can be moved on the track by an eccentric drive.

3. The breathing device according to claim 1 or 2, characterized in that The shape of the rotor (4) and the shape of the pump chamber (2) are constructed and coordinated with each other so that when a cross section is observed inside the pump chamber (2) at an angular position of 0° of the rotor (4), two contact points (A, A') or two contact ranges arranged around these contact points (A, A') are realized between the rotor (4) and the inner wall of the pump chamber (2), and in all other angular positions only one contact point (A) or one contact range arranged around this contact point (A) is realized between the rotor (4) and the inner wall of the pump chamber (2).

4. The breathing device according to claim 1 or 2, characterized in that The separation element (8) is connected to the rotor (4) and projects from the rotor into the region of the inlet (5) and the outlet (6).

5. The breathing device according to claim 1 or 2, characterized in that The rotor (4) is mounted in a resilient manner relative to a housing (3) of the pump chamber (2).

6. The breathing device according to claim 1 or 2, characterized in that The housing (3) of the pump chamber (2) is designed to be resilient relative to the rotor (4).

7. The breathing apparatus according to claim 6, characterized in that The housing (3) of the pump chamber (2) has fins (24) which protrude inwardly into the pump chamber (2) and extend transversely to the direction of movement of the rotor (4).

8. The breathing apparatus according to claim 1 or 2, characterized in that The cross-sectional shape of the rotor (4) is formed according to a spline function, which is generated in a Cartesian coordinate system and converted into a polar coordinate system, thereby achieving a curve course without jumps.

9. The breathing apparatus according to claim 1 or 2, characterized in that The rotors (4', 4") can be driven by means of a common shaft (13).

10. The breathing apparatus according to claim 8, characterized in that The spline function is composed of a cubic parabola.

11. A method for providing breathing gas, comprising the following method steps: moving a rotor in a pump chamber from an angular position of 0° on an orbit along the direction of movement of the rotor to a position in which the rotor and the inner wall of the pump chamber have exactly one contact point (A) or a contact range arranged around the contact point (A), in which the rotor and the inner wall of the pump chamber have two contact points (A, A') or two contact ranges arranged around these contact points (A, A') and thereby seal an inlet area and an outlet area relative to the rest of the pump chamber; by means of the rotor and the The contact point of the inner wall of the pump chamber separates the pressure chamber in front of the rotor in the direction of movement from the suction chamber behind the rotor in the direction of movement; the breathing gas is sucked from the inlet into the suction chamber by the continuous movement of the rotor in the pump chamber and the breathing gas is discharged from the pressure chamber through the outlet, wherein the second rotor implements the same method steps in the second pump chamber with a phase offset of 180°, so that when the rotor performs a circular motion on the corresponding orbit inside the corresponding pump chamber at a constant operating speed, a flow curve of the breathing gas that is as free of jumps as possible is achieved at the common outlet, characterized in that The method uses a breathing apparatus according to any one of claims 1-10.

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