PUMP DEVICE, RESPIRATORY DEVICE AND METHOD FOR PROVIDING A RESPIRATORY GAS

Abstract

A pump device, a respiratory device and a method for providing a respiratory gas. A specially formed rotor and a corresponding pump chamber are used so that an approximately sinusoidal flow of an out-flowing fluid is possible. With the combination of two pump chambers with rotors driven in a 180° phase-shifted manner to one another, an almost constant flow can be created at a common outlet. In addition, the system is designed to be highly dynamic with simultaneously relatively low energy consumption.

Claims

1-15. (canceled)

16. A pump device, comprising: at least one pump chamber and, for each pump chamber, a rotor arranged in the pump chamber, the at least one pump chamber having an inlet and an outlet so that a fluid can flow into the pump chamber via the inlet and can flow out of the pump chamber via the outlet, wherein the rotor is drivable on an orbital path inside the pump chamber, wherein the rotor and the pump chamber are shaped to match each other so that an approximately sinusoidal profile of the flow of the fluid flowing out of the outlet is effected by movement of the rotor in the pump chamber at a constant speed.

17. The pump device according to claim 16, further comprising eccentric drive means for moving the rotor on the orbital path.

18. The pump device according to claim 16, wherein the shape of the rotor and the shape of the pump chamber are matched to each other so that, when considering a cross-section in the 0° angular position of the rotor inside the pump chamber, two contact points or two contact regions arranged about these contact points are formed between the rotor and an inner wall of the pump chamber, and in all other angular positions, just one contact point or one contact region arranged about the one contact point is formed between the rotor and the inner wall of the pump chamber.

19. The pump device according to claim 16, wherein the inlet and the outlet are connected to the pump chamber by a common duct, wherein a separating element is arranged in the duct to separate the inlet from the outlet.

20. The pump device according to claim 19, wherein the separating element is connected to the rotor and projects from the rotor into a region of the inlet and the outlet.

21. The pump device according to claim 16, further comprising a housing, wherein the rotor is spring-mounted relative to the housing.

22. The pump device according to claim 16, further comprising a housing, wherein the housing is spring-mounted relative to the rotor.

23. The pump device according to claim 22, wherein the housing has fins that project inward into the pump chamber and extend transversely to a direction of movement of the rotor.

24. A pump device, comprising: two pump chambers; and, for each pump chamber, a rotor arranged in the pump chamber, wherein each pair made up of the pump chamber and the rotor is a device according to claim 16.

25. The pump device according to claim 24, wherein the rotors are arranged in the pump chambers, phase-shifted relative to each other by 180°.

26. The pump device according to claim 24, wherein the two pump chambers have a common outlet at which flows of respective out-flowing fluids join together to form a total flow.

27. The pump device according to claim 24, further comprising a common shaft arranged to drive the rotors.

28. A respiratory device comprising at least one pump device according to claim 24.

29. A method for providing respiratory gas, comprising the steps of: displacing a rotor in a pump chamber from a 0° angular position, in which the rotor has two contact points, or two contact regions arranged around these contact points, with an inner wall of the pump chamber and consequently ceiling an inlet region and an outlet region relative to a remainder of the pump chamber, in a direction of movement of the rotor on an orbital path, into a position in which the rotor and the inner wall of the pump chamber have precisely one contact point, or one contact region arranged around the contact point; separating a pressure space in front of the rotor in the direction of movement and a suction space behind the rotor in the direction of movement by the contact point of the rotor and the inner wall of the pump chamber; drawing respiratory gas from the inlet into the suction space; and delivering the respiratory gas from the pressure space via the outlet by continuous displacement of the rotor in the pump chamber, wherein the method steps are implemented in a sequence phase-shifted by 180° with a second rotor in a second pump chamber so that, when the rotors circulate on the respective orbital paths inside the respective pump chamber at a constant running speed, an optimally smooth flow profile of the respiratory gas is achieved at a common outlet.

30. The method for providing respiratory gas according to claim 29, including using a pump device comprising two pump chambers and, for each pump chamber, a rotor arranged in the pump chamber, wherein each pair made up of the pump chamber and the rotor is a pump device in which the pump chamber has an inlet and an outlet so that a fluid can flow into the pump chamber via the inlet and can flow out of the pump chamber via the outlet, and in which the rotor is drivable on an orbital path inside the pump chamber, and in which the rotor and the pump chamber are shaped to match each other so that an approximately sinusoidal profile of the flow of the fluid flowing out of the outlet is effected by movement of the rotor in the pump chamber at a constant speed.

Description

[0086] Exemplary embodiments of the invention are illustrated in the drawings, in which:

[0087] FIG. 1 shows a cross-section of a pump device according to the invention in the region of the pump chamber in the 0° angular position of the rotor,

[0088] FIG. 2 shows a cross-section of a pump device according to the invention in the region of the pump chamber in the 60° angular position of the rotor,

[0089] FIG. 3 shows a cross-section of a pump device according to the invention in the region of the pump chamber in the 180° angular position of the rotor,

[0090] FIG. 4 shows a cross-section of a pump device according to the invention in the region of the pump chamber in the 300° angular position of the rotor,

[0091] FIG. 5 shows a graph of the flow profiles of the fluid at the outlet of two pump chambers and a common outlet of both pump chambers,

[0092] FIG. 6 shows a perspective view of a cross-section of a pump device according to the invention,

[0093] FIG. 7 shows a perspective view of a longitudinal section of a pump device according to the invention with two pump chambers and two rotors,

[0094] FIG. 8 shows a schematic illustration of the cross-section of a rotor of a device according to the invention,

[0095] FIG. 9 shows the radial profile of the radius r of the rotor illustrated in FIG. 8 over the angle α,

[0096] FIG. 10 shows a schematic illustration of the cross-section of a rotor in a pump chamber of a device according to the invention,

[0097] FIG. 11 shows a cross-section of a further embodiment according to the invention of a pump device, and

[0098] FIG. 12 shows a flow diagram of a method according to the invention for providing respiratory gas.

[0099] FIG. 1 shows in a schematic illustration a section through an embodiment according to the invention of a pump device (1). The pump device (1) has a pump chamber (2) which is integrated into 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 spokes (4c) which connect the rotor core (4b) to the rotor wall (4a). This structure makes it possible for the rotor (4) to be configured so that it is internally hollow such that the mass of the rotor (4) is low. 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 can flow out of the pump chamber (2) through the outlet (6). The rotor (4) can be moved inside the pump chamber (2) with the aid of a drive means (7). The drive means (7) is preferably designed as an eccentric drive means such that the rotor (4) can be moved in the pump chamber (2) on an orbital path. On the right-hand side, the rotor (4) has a separating element (8) designed as a connecting rod by means of which the region of the inlet (5) is separated from the region of the outlet (6). At its end averted from the remainder of the rotor (4), the separating element (8) has a sealing element (10) which is guided linearly 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) with the aid of the sealing element (10). The angular position of the rotor (4), which is here the zero position, is indicated by the arrow in the region of the drive means (7). In the zero position or the 0° angular position, the rotor (4) has two contact points (A, A′) with the inner wall of the pump chamber (2). The pressure space (12) formed between the rotor wall (4a) and the inner wall of the pump chamber (2) in this position in the pump 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′).

[0100] The shapes of the rotor (4) and the pump chamber (2) are matched to each other in such a way that the profile of the volume flow or flow of a fluid flowing out of the outlet (6) of the pump device (1) is approximately sinusoidal at a constant speed of movement of the rotor (4). On the left-hand side, the contour of the rotor wall (4a) corresponds approximately to the contour of an ellipse with a first diameter, and on the right-hand side to two overlapping circles with a smaller diameter. The first circle here merges into the two smaller circles.

[0101] The pump device (1) shown in FIG. 1 is illustrated in FIG. 2 in an angular position of approximately 60°. The rotor (4) and the inner wall of the pump chamber (2) now have just one contact point (A). A pressure space (12) is formed between the rotor (4) and the inner wall of the pump chamber (2) downstream from the contact point (A) in the direction of movement which is defined by the clockwise direction, and a suction space (11) is formed upstream from the contact point (A) in the direction of movement. A fluid can be drawn into the pump chamber (2) via the inlet (5) by the movement of the rotor (4) in the pump chamber (2). The separating element (8) connected to the rotor (4) and designed as a connecting rod is slightly inclined according to the position of the rotor (4).

[0102] The pump device (1) illustrated in FIGS. 1 and 2 is illustrated in FIG. 3 in a 180° angular position. In this position, the suction space (11) and the pressure space (12) are of the same size. The volume flow of a fluid flowing out of the outlet (6) of the pump device (1) reaches its maximum value in this position.

[0103] The pump device (1) according to the invention shown in the previous drawings is illustrated in FIG. 4 in a 300° angular position. The suction space (11) then takes up the majority of the volume of the pump chamber (2), whilst the pressure space (12) now makes up only a very small part of it. The volume flow of a fluid flowing out from the pump device (1) via the outlet (6) is already approaching the minimum value.

[0104] The shape of the rotor (4) and the pump chamber (2) are matched to each other in such a way that two contact points (A, A′) between the rotor wall (4a) and the inner wall of the pump chamber (2) are provided only in the 0° angular position on the orbital path of the rotor (4), whereas just one contact point (A) is provided in all other angular positions.

[0105] The flow profile of a pump device (1) according to the invention with two pump chambers (2), in each of which a rotor (4) is arranged, is illustrated in FIG. 5, wherein the rotors (4) are driven phase-shifted relative to each other by 180°. The profile of the flow over the angular position corresponds in each case approximately to a sine wave, wherein for each pump chamber (2) the minimum value is 0% and the maximum value is more than 95% of the total volume flow. The cumulative flow profile (total volume flow) of a common outlet (6) to which the two pump chambers (2) are connected is also illustrated. The total flow of the pump device (1) is almost constant and varies only between approximately 95% and 100%.

[0106] FIG. 6 shows a perspective view of a pump device (1) according to the invention, wherein a closure element, such as for example a sealed closure cap, sealing the pump chamber (2) at the top is not mounted so that the pump chamber (2) is open. The rotor (4) is situated approximately in the 180° angular position.

[0107] One end of the shaft (13) of the drive means (7) can be seen to which a decoupling apparatus (15) designed as a rolling bearing is connected via a connecting mechanism (20). The shaft (13) is here arranged eccentrically inside the decoupling apparatus (15) such that eccentric driving of the rotor (4) is effected. Also connected to the connecting mechanism (20) is a mass balancing element (16) by means of which the uneven mass distribution, which would otherwise create an imbalance when the shaft (13) rotates, can be compensated. The rotor core (4b) is connected to the rotor wall (4a) via spokes (4c). Arranged inside the rotor (4) are ribs (4d) which serve, together with the mass balancing element (16), to shift the center of gravity of the rotor (4) into the center of the rolling bearing used and/or into the middle of the motor axis or the shaft (13). Vibration is largely prevented or at least considerably suppressed as a result. A multi-part sealing element (10), which has a resilient counter bearing (10a) and a roller (10b), is arranged at that end of the separating element (8) which is averted from the rotor (4). By virtue of this arrangement, in case of doubt the separating element (8) can be pressed against the housing wall on the opposite side by the pressure at the outlet (6) so that the separating element (8) forms a seal against the housing. The spring-loaded running surface or the resilient counter bearing (10a) thus ensures a minimum contact pressure and the initial pressure also assists in case of doubt.

[0108] FIG. 7 shows in a schematic illustration a longitudinal section through an embodiment according to the invention of a pump device (1) having two pump chambers (2′, 2″) with in each case one associated rotor (4′, 4″). The first rotor (4′) is arranged in the first pump chamber (2′) and is situated at approximately the 180° angular position. The second rotor (4″) is arranged in the second pump chamber (2″) and is situated at approximately the 0° angular position. The first pump chamber (2′) is separated from the second pump chamber (2″) by a separating wall (19). A motor (14), by means of which a shaft (13) can be driven, is furthermore arranged below the pump chambers (2′, 2″). The shaft (13) is used to drive the two rotors (4′, 4″). A decoupling apparatus (15) designed as a ball bearing is connected eccentrically on the shaft (13) in each case in the region of a pump chamber (2′, 2″) with the aid of a connecting mechanism (20) such that the rotors (4′, 4″) can be moved inside the pump chambers (2′, 2″) on orbital paths. The phase shift between the rotors (4′, 4″) is fixed at 180° by the orientation of the rotors (4′, 4″) on the shaft (13). A change in the phase shift during operation of the pump device (1) is thus excluded by the use of a common shaft (13). The mass balancing elements (16′, 16″) are likewise arranged offset to each other by 180°.

[0109] The rotors (4′, 4″) each have a sliding ring (21), which has a protrusion in the region of the separating element (8), at their ends in the axial direction. The sliding rings (21) are here each inserted into a circumferential groove, wherein the sliding rings (21) are not completely countersunk in the groove. The sliding rings (21) run against the walls bounding the pump chambers (2′, 2″) in the axial direction and thus seal the pump chambers (2′, 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 spring-loaded by spring elements (22) in such a way that they are pressed against the housing wall. In the embodiment of the invention illustrated, the spring elements (22) lie behind the sliding rings (21) in the respective groove. The shaft (13) is sealed with the aid of a shaft seal (23).

[0110] In different embodiments of the invention, different positions of the motor (14) of the drive means are also conceivable, for example between the pump chambers (2′, 2″).

[0111] A schematic illustration of the cross-section of a rotor (4) of a device (1) according to the invention is illustrated in FIG. 8. The shape of the rotor (4) is defined by a spline function. The radius r and the angle α by means of which the shape of the rotor (4) can be described in the illustrated coordinate system with an x-axis and y-axis are furthermore shown.

[0112] FIG. 9 shows the profile of the radius r over the angle α of the rotor illustrated in FIG. 8. The triangles show which values (radius over angle) have been specified for the spline function (target points). The curve is a cubic spline function in the Cartesian coordinate system which is converted into the polar coordinate system.

[0113] The curve is not symmetrical about the central value of 180°, i.e. the rotor (4) of the corresponding embodiment of a device according to the invention is also not symmetrical about the x-axis. By optimizing the shape, the latter takes a form such that the flow of the out-flowing fluid is as constant as possible.

[0114] A schematic illustration of a cross-section of a rotor (4) shaped in accordance with a spline function in a correspondingly formed pump chamber (2) is illustrated in FIG. 10. The contour of the pump chamber (2) here results from the envelope of the rotor shape which is displaced over the crank angle according to the eccentric drive means over one complete revolution (0 -360°).

[0115] The circle illustrated inside the rotor (4) is the circle of the eccentric center point.

[0116] FIG. 11 shows a cross-section of an embodiment of a pump device (1) according to the invention with a housing (3) of the pump chamber (2) which is designed so that it is resilient relative to the rotor (4).

[0117] For this purpose, the housing (3) has on its inside fins (24) which project into the pump chamber (2).

[0118] The fins (24) are positioned so that they are slightly inclined in the direction of movement of the rotor (4) in the embodiment illustrated. As a result, a low frictional force counteracting the movement of the rotor (4) is achieved with a simultaneously good sealing effect.

[0119] In such an embodiment of the invention, depending on the angular position of the rotor (4) in the pump chamber, there is no longer precisely one contact point (A) or there are no longer precisely two contact points and instead a contact region is formed around this point or these points in which the rotor (4) is contacted by a plurality of fins (24).

[0120] The embodiment illustrated of a pump device (1) according to the invention furthermore has a modification, which can also be implemented for all the other embodiments shown, of the sealing element (10) which connects the separating element (8) to the housing (3) of the pump chamber (2) on its side averted from the rotor (4) in sealing fashion. The sealing element (10) here has a lever (10c) which is mounted on the housing (13) so that it can move in rotation about a first axis of rotation and which is connected to the end of the separating element (8) so that it can move in rotation about a second axis of rotation such that, in contrast to the design as a connecting rod mounted in sealing fashion in a guide (9), a lower friction occurs in this region.

[0121] The sequence of a method according to the invention for providing respiratory gas is illustrated schematically in FIG. 12. In the case of the use of a pump device according to the invention with a housing spring-mounted relative to the rotor, instead of the contact point or the contact points, contact regions extending around these points are formed between the rotor and the housing.