EP3841303A1

EP3841303A1 - Microblower

Info

Publication number: EP3841303A1
Application number: EP19783618.2A
Authority: EP
Inventors: Frank Bartels; Anja Strube; Florian Siemenroth
Original assignee: Bartels Mikrotechnik GmbH
Current assignee: Bartels Mikrotechnik GmbH
Priority date: 2018-08-24
Filing date: 2019-08-23
Publication date: 2021-06-30
Anticipated expiration: 2039-08-23
Also published as: DE102018120782B3; US20210199106A1; WO2020039399A1; JP2021535323A; US11434893B2; EP3841303B1; EP3841303C0

Abstract

A micropump comprises: a momentum unit (10) having a piezo actuator (11) which is arranged on a vibrating diaphragm (12); a vibrating plate (15) which is arranged opposite the vibrating diaphragm (12) and has a blower opening (16); and a wall arranged between the vibrating diaphragm (12) and the vibrating plate (15), such that a blower chamber (13) is formed; and a housing (20), in which the momentum unit (10) is mounted, having an intake opening (24), and an outlet opening (25), which is opposite the blower opening (16). The housing (2) forms a closed space (H), and has at least one intake opening (24), which is arranged radially or on an underside opposite the momentum unit (10) and has an intake channel, leading into a pump chamber (26) situated between the vibrating plate (15) and the housing inner side. The invention also relates to the use of the micropump according to the invention.

Description

micro-blower

introduction

The invention relates to a miniaturized pump for compressible fluids. In particular, the invention relates to a micro blower for gases or gas mixtures such as in particular air.

State of the art and disadvantages

Micropumps are well known in the art. According to one definition, they serve to convey fluids (liquids and gases) of small volumes. These are typically in the range from micro to milliliters per minute.

In addition to the amount of fluid pumped per unit of time, the size of the pump, in particular its pump housing, can also be decisive in determining the presence of a micropump. In this respect, the term "micropump" also refers to a particularly small housing, which has edge lengths in the range from a few millimeters to a few centimeters. Components such as power supply and control are often housed separately from the housing, which is why the term "micropump" in the narrower sense the components required for the actual conveying (pump chamber, valves, housing) are restricted. In particular, such a micropump is also the subject of the present invention.

Micropumps that are particularly suitable for pumping incompressible fluids (liquids) are based on the so-called peristaltic principle. Two or more alternating piezo-ceramic disks rhythmically increase and decrease the volume of two adjacent pumping chambers. The conveying direction is determined by skillful coupling of the chambers by means of movable check valves and a phase shift of the control. By varying the stroke or the Vibration frequency, the pump can pump a wide range of liquid quantities.

Micropumps constructed in this way are in principle suitable for conveying both liquids and gases; When the micropump is in operation, the valves limit the pump frequency due to their inertia. In addition, they are exposed to constant, mostly high-frequency stress, which places high demands on their mechanical properties. Another disadvantage is the noise emission due to the drive of the pump. At frequencies above approx. 300 Hz, these are clearly audible even with small dimensions, and at frequencies above approx. 1000 Hz, the noise emission increases to a level which is not tolerable in many application scenarios. Operation above the hearing threshold of approx. 20 KHz is not possible due to the inertia of the valves. Accordingly, there is a practical limit to the amount delivered.

Furthermore, micropumps are known which do without mechanical valves. Instead, they are operated in a narrow frequency range, preferably the resonance frequency of the 1st or higher order. They are designed in such a way that fluid dynamic effects come into play at the operating frequency, which lead to the formation of a preferred direction when the fluid is conveyed. From DE 11 2013 002 723 T5, US 2011/0076170 A1 and US 2016/0377072 A1, micropumps are known which are operated at high frequencies, preferably in the inaudible range. The only actuator in the form of a piezo disk is attached to a membrane which provides passage openings for the fluid to be conveyed. Fluid-filled chambers are present on both sides of the membrane. The flow conditions during operation of the pump lead to a depending on the direction of vibration of the membrane different fluid resistance in the corresponding chamber. In this way, the fluid is conveyed in the desired conveying direction.

A modification of the principle, in particular for the conveyance of gases, is disclosed in EP 2 306 018 A1. A piezo disk forms a vibrating plate together with a membrane to which it is attached. A hollow chamber is arranged on the side facing away from the piezo disk. This has a central opening. The swing unit consisting of a vibrating plate and a hollow chamber is elastically supported in an outer housing that is open to the side of the piezo disk, so that the entire swing unit can swing in the direction of curvature of the piezo disk from which it is driven. The outer housing has an outlet opening, likewise centrally. There is an air gap between the swing unit and the inside of the outer case. The part of the air gap that leads into the area that surrounds the side walls of the hollow chamber that run perpendicular to the surface of the piezo disk serves as the inlet opening.

If the piezo disk, and with it the entire Schwungein unit, is set into vibrations which preferably have the resonance frequency, gas is sucked in through the inlet opening and the adjoining region mentioned above in a suction phase. The suppression required for this develops in the gradually increasing area between the central opening of the hollow chamber and the outlet opening. In the subsequent application phase, this area shrinks again. By suitable design of the air gap and the size of the central opening in the hollow chamber and outer housing, the above-mentioned fluid dynamic effects are used, and a preferred direction can be formed in which the gas is transported. A disadvantage of the construction shown is the fact that the piezo disk is located in the area of the outer housing that is open to the outside, and that gas must also flow around it during operation. Mechanical damage or impairments due to environmental influences (air humidity, aggressive gases, etc.) cannot be ruled out in this way. In addition, there are inlet and outlet openings on opposite sides of the micropump. In certain cases, this can be disadvantageous, for example when the micropump is to be mounted on a “fluidic circuit board” in which fluid-carrying channels are present. The air gap between the swing unit and the inside of the outer housing also enlarges or reduces the outer housing the space available.

A further development of this micropump, which is intended in particular for gases, is known from the publication DE 10 2012 101 861 A1. Accordingly, the pump has a gas-permeable but liquid-impermeable fabric over the suction area to prevent impairment due to dust or liquids drawn in with the gas during operation, which tissue is preferably oscillatable. However, said protection also reduces the delivery capacity of the micropump, since part of the output is now required for the transport of the gas through the tissue which has a certain flow resistance.

Another solution, which is comparable in part to the micropump with hollow chamber, is known from the publication EP 2 090 781 B1. Here the piezo disc is also on the outside of a hollow chamber with a central opening, which, however, cannot vibrate as a whole; only the wall designed as a vibrating membrane, on which the piezo disk is attached, can vibrate. Beyond this A wall which is opposite the wall and has the central opening is arranged at a distance from one another and has the central exit opening. The gap between the latter walls serves as the entrance opening. If the membrane vibrates, the internal pressure in the hollow chamber changes, which propagates through the central opening into the aforementioned gap. There, a suppression leads to a suction of gas into the gap, and a subsequent overpressure to a blowing out of the gas, preferably through the outlet opening.

Object of the invention and solution

The invention is therefore based on the object of providing an apparatus and a method which avoids the disadvantages of the prior art. Accordingly, a micropump according to the invention for compressible fluids should have an improved insensitivity to mechanical and other external impairments. It should be suitable for mechanical connection to a surface and also allow for an improved utilization of the construction volume.

The object is achieved by a device according to claim 1 and a method according to independent claim 9. Advantageous embodiments can be found in the dependent subclaims, the following description and the figures.

description

The micropump according to the invention and advantageous embodiments thereof are first described below. This is followed by a description of their use.

The micropump according to the invention is used to convey compressible fluids such as gases in particular. The micropump comprises two main units, which, however, must not be viewed independently of one another, but must be closely coordinated and thus form a common whole in order to ensure the desired fluid transport.

The first main unit is referred to below as the "swing unit" because (in the idealized case) only it is in motion during operation. The swing unit comprises a disk-shaped, usually round or rectangular piezo actuator that typically has a diameter of a few (eg 1 - 5) millimeters to a few (eg 1 - 4) centimeters, and which, when activated, ie when a suitable voltage is applied, changes from a typically flat resting state to a typically arched deflection state generated in the opposite direction, which increases the usable stroke accordingly.

The piezo actuator is arranged on an inside and / or outside of a vibrating membrane. It is firmly connected to it, so that it also performs the curvature described above. It is also conceivable to design the piezo actuator and vibrating diaphragm in one piece, or even to see the latter as a subunit of the piezo actuator. The inside is the side that faces towards the blower chamber described below.

A vibrating plate is arranged opposite the inside of the vibrating diaphragm. Depending on the embodiment, this will preferably also move during operation. The vibrating plate has at least one centrally arranged blower opening. If it has several blower openings, they are preferably also located in the central area.

Between the vibrating diaphragm and the vibrating plate there is a circumferential and essentially gas-tight wall connected to both, so that a inside the swing unit Blower chamber is formed. The swing unit is accordingly hollow on the inside, and the cavity, ie the blower chamber, has (at least) one opening through which the fluid can flow in and out again.

The second main unit is referred to below as the “housing”. The swing unit can be completely accommodated in this, a gap surrounding the swing unit being present. This is necessary because the swing unit is mounted in the housing in the swinging direction of the piezo actuator by means of at least one suspension , it is clear that the gap must be dimensioned so that no collision between the swing unit and the housing can occur during normal operation.

The suspension is provided to decouple the swing unit from the housing surrounding it in terms of vibration. In this way, the efficiency of the micropump is increased, since no energy is lost due to (unwanted) movement (i.e. swinging) of the housing.

The housing has at least one inlet or suction opening. This allows fluid to flow into the interior of the housing.

The housing has (at least) one outlet opening, which is also arranged in the center, and is thus opposite the fan opening. There is a gap between the two openings that is at least large enough that no collision between the swing unit and the housing can occur during normal operation.

According to the invention, the housing forms a closed space that also covers the piezo actuator and thus protects it from environmental influences. In particular, the outward-facing side of the vibrating diaphragm, and with it the piezo actuator, are also covered by the housing. According to the invention, the suction opening is also arranged radially (and thus perpendicular to the direction of vibration of the piezo actuator), or on an underside opposite the swing unit. It has an intake duct that leads into a “pump chamber” located between the oscillating plate and the inside of the housing.

When the piezo actuator is vibrating, the swing unit can be set in vibration relative to the housing, as a result of which the compressible fluid can be drawn in through the suction opening and can be dispensed through the outlet opening.

The invention thus avoids the disadvantages known from the prior art. Since the piezo actuator is completely surrounded by the housing, it protects it from undesired mechanical impairments and environmental influences. However, protection is only possible due to the construction according to the invention, since here the fluid does not flow through a suction opening which leads past the piezo actuator, as is partially practiced in the prior art. Since the suction opening is not opposite, but laterally from, or on the same side as the outlet opening, the micropump according to the invention can also be mounted on a plate without closing one of the openings or without the one or more corresponding holes for the openings would be necessary in the plate. Finally, the micropump according to the invention makes optimal use of the installation space available to it, since the gap on the side (in the region of the wall) only has to be large enough that the oscillating movement of the oscillating body is not impeded; Since the movement runs parallel to the (side) inner wall of the housing, a small gap, for example from 10 to 1000 pm, is sufficient. In contrast, the air gap according to the constructions known from the prior art must be sufficiently large for gas transport, which leads to a significantly larger distance and thus, with a comparable conveying capacity, a larger housing. Various embodiments of the invention are described in more detail below.

According to one embodiment, the housing has a housing body and a housing cover. The housing body then has a pot-like shape with a bottom and surrounding walls.

According to a variant of this embodiment, the housing body is set up to accommodate all movable components, including the gap dimensions required for vibration. As a result, this allows the use of a very flat housing cover. In addition, all movable components can be inserted into the housing body one after the other during manufacture and the housing can finally be closed with the housing cover. The lid can also be simple, i.e. without depressions.

According to another variant of this embodiment, at least parts of the movable components are arranged in an inner recess of the housing cover, or at least they oscillate in and out of it during operation. This means that the housing body can be flatter because the lid also provides space for certain components. The production of housing parts of approximately the same thickness can be advantageous in particular in the case of injection molded parts, or in the simultaneous production of both parts by means of 3D printing.

According to one embodiment of the swing unit, the oscillating plate and wall are manufactured in an integrated manner. Both components together thus have a pot-like shape in the assembly, on which the vibrating diaphragm is then placed, so to speak, as a “cover” in order to provide the largely closed blower chamber.

Even the vibration membrane can also be integrated, for example by using 3D printing. According to another embodiment of the swing unit, the swing plate and wall are manufactured as separate components. The oscillating plate can then be provided in particular as a flat, disc-shaped body, to which a ring of a certain thickness is applied. The space that the ring encloses then defines the blower chamber. In this way, blower chambers of different heights can easily be produced, since only one ring of different thicknesses is to be used in each case; the vibrating plate can remain unchanged.

According to a further embodiment, the piezo actuator is arranged gas-tight to the pump chamber. This means that the piezo actuator no longer comes into contact with the fluid to be conveyed, since the space in which it is located is closed off. This can be achieved, for example, by designing the suspension to be continuous all the way round, or by providing an additional thin protective membrane that does not hinder the vibration. Thus, the gap between the wall of the swing unit and the inner wall of the housing is interrupted all around; only the partial volume of the interior of the housing in which the piezo actuator is not located (pump chamber) comes into contact with the fluid.

It should be noted that even a design with a non-separated partial volume already leads to an improved separation of the piezo actuator and the fluid to be conveyed, since the latter is not continuously guided past the former, but at best penetrates into the corresponding half space in small quantities without being constantly exchanged ,

The piezo actuator preferably has a diameter of 5 to 50 mm, and preferably 8 to 20 mm, and particularly preferably 10 to 15 mm. The gap between the wall and the inside of the housing is preferably less than 0.01 to 1 mm, and particularly preferably less than 0.5 mm.

The micropump, minus any nozzles that may be present, preferably has a total height of 3 to 10 mm; it is particularly preferably less than 8 mm.

According to a further embodiment, the diameter of the blower opening is between 3.0 and 0.1 mm, and preferably between 2.0 and 0.3 mm, and particularly preferably between 0.5 mm and 0.7 mm.

The diameter of the suction opening (s) is preferably between 0.1 and 10.0 mm, and preferably between 0.2 and 5.0 mm, and particularly preferably between 0.5 mm and 2.5 mm.

The diameter of the exit opening (s) is preferably between 0.1 and 10.0 mm, and preferably between 0.25 and 5.0 mm, and particularly preferably between 0.7 and 0.9 mm.

Depending on the number of openings, this applies to each opening individually or to the sum of the cross sections of the respective openings.

The use of the micropump according to the invention will now be described below.

Accordingly, the method serves to deliver a compressible fluid, such as in particular a gas, using a micropump as defined above; To avoid repetition, please refer to the relevant passages above.

In a suction phase, the piezo actuator is controlled with a suitable voltage in such a way that it bulges against the direction of the blower opening. This creates a suppression in the blower chamber, which is characterized by the above Fan opening also propagates into the pumping chamber, whereby fluid is drawn in through the suction opening.

In a subsequent output phase, however, the piezo actuator is activated in such a way that it now bulges in the direction of the blower opening. As an alternative, there is no (active) control, so that the piezo actuator goes (typically) to a flat, rest position. This leads to the fact that the negative pressure in the blower chamber regresses or even, measured at the ambient pressure, an overpressure is generated, which also propagates through said blower opening into the pumping chamber, whereby fluid, using the fluid dynamic effects described above, is emitted through the outlet opening becomes.

The rhythmic movement of the piezo actuator also causes the entire swing unit to vibrate.

The preferred direction, i.e. the suction through the suction opening and the discharge through the outlet opening, is therefore determined by the special design of the micropump, in particular by the presence of the blower chamber, the blower opening, the oscillating movement of the swing unit in relation to the housing surrounding it, and the arrangement the suction and outlet openings are reached.

The advantage of the method according to the invention is that, using the micropump according to the invention, it allows improved protection of the piezo actuator against undesired external influences, since the fluid is only conveyed outside the half space containing the piezo actuator. The suspension divides the inside of the housing into two half-spaces; one half-space contains the piezo actuator, the other half-space opens into the suction and outlet opening (s), and only this is actively flowed through by the delivered fluid. According to a preferred embodiment, the oscillating plate also swings in the direction of movement of the piezo actuator, ie both plates move approximately in the same direction. In this way, an improved generation of negative or positive pressure in the pump chamber can be achieved.

According to another preferred embodiment, the oscillating plate also oscillates, but in each case counter to the direction of movement of the piezo actuator, i.e. both plates move with the same frequency, but precisely in the opposite direction to one another. In this way, the vibrating diaphragm and the vibrating plate, together with the wall, form a kind of bellows, which alternates between a minimum and maximum volume of the blower chamber during each vibrating cycle. This leads to a particularly strong inflow and outflow of the fluid into and out of the blower chamber.

figure description

The invention is explained below by way of example using figures. It shows

Figure 1 is an exploded view of the main components of a

Embodiment of the micropump according to the invention;

Figure 2 is a sectional view through the assembly of these

embodiment;

Figure 3 shows a schematic cross section through this

Embodiment to illustrate the fluid paths;

Figure 4 shows a schematic cross section through a

Embodiment with axial suction opening;

FIG. 5 shows an exploded view of a further embodiment of the micropump according to the invention; Figure 6 is a sectional view through the assembly of these

embodiment;

FIG. 7 shows an exploded view of a further embodiment of the micropump according to the invention;

Figure 8 is a sectional view through the assembly of these

From execution form.

FIG. 1 shows an exploded view of the most important components of an embodiment of the micropump according to the invention.

Accordingly, the micropump comprises two main units. The first main unit is the swing unit 10.

The swing unit 10 comprises a disk-shaped piezo actuator 11, which is arranged on an outside of a vibration diaphragm 12 (pointing upwards in the figure). A ring 14 of defined thickness is provided as the wall for the blower chamber 13. This is arranged on the vibrating plate 15, which lies opposite the inside of the vibrating membrane 12. In the oscillating plate 15 there is a centrally arranged blower opening 16. According to this embodiment, the oscillating plate 15 and wall (ring 14) are present as separate components.

Four suspensions 17 are arranged symmetrically to the side of the oscillating plate 15 (only one is provided with reference numerals). By means of this, the remaining swing unit 10 can swing at least, and preferably only, in the vertical direction (in the picture). The distal ends of the suspensions 17 can be inserted into correspondingly shaped receptacles 22 of the housing body 21 (likewise only one is provided with reference numerals).

The second main unit is the housing 20.

The housing body 21 comprises a recess 23 in which the components of the swing unit 10 can be at least partially accommodated are. Between the swing unit 10 and the inside of the housing 20 there is therefore a gap S (see, for example, the next and the next but one figure) which ensures the required freedom of movement of the swing unit 10. In the present case, four suction openings 24 are present in the housing body 21 (only one is provided with reference numerals). In the present case, these initially run radially to the main direction of movement of the swing unit 10, which runs in the image in the vertical direction. After a 90-degree bend (not visible, see next figure), they open into the pump chamber 26. An outlet opening 25, which is opposite the blower opening 16, branches off from the latter.

The housing 20 also includes a housing cover 27, which closes the interior, comprising the pump chamber 26 and the half space H, of the housing 20. In the present case, the housing cover 27 is provided as a separate component, which is connected to the housing body 21 in a gas-tight manner. In the embodiment shown, the housing cover 27 also has a recess (without reference numerals) in which the components of the swing unit 10 can also be at least partially accommodated.

In FIG. 2, which shows a sectional view through the assembly of this embodiment, it can be seen that the housing 20 forms a closed space which also covers the piezo actuator 11 and thus protects it from environmental influences. For reasons of clarity, only some of the reference symbols are shown.

Also recognizable is the gap S surrounding the swing unit 10, and the guidance of the suction openings 24, which lead radially into the housing and, after a 90-degree curve, open perpendicularly into the pump chamber 26.

If the illustrated embodiment is mounted on a plate in the upside-down position, then none of the openings is covered or closed by this plate. According to an embodiment not shown, the housing body has only a single, preferably circumferential suction opening. The suction opening then runs parallel to the bottom of the pumping chamber below it, and has at least one, but preferably a plurality of openings into the pumping chamber. In this way, the fluid resistance when flowing in is particularly low.

Finally, FIG. 3 indicates the flow paths of the fluid when the micropump is operating. Here too, only a few of the reference symbols are shown. According to this embodiment, the oscillating plate 15 and the wall are made integrated. The piezo actuator 11 is arranged gas-tight to the pump chamber 26. In a suction phase, the swing unit 10 moves in the direction of the arrow 31. A negative pressure is therefore generated in the lower half-space, which forms the pump chamber 26. This leads to fluid (not shown) flowing in the direction of arrows 32 through the suction openings 24 into the pump chamber 26.

In contrast, in an output hare, the swing unit 10 moves in the opposite direction of the arrow 31. There is an increase in pressure in the pump chamber 26, which leads to an outflow of the fluid through the outlet opening 25.

As can be seen, the fluid is conveyed at all times outside the upper half space H containing the piezo actuator 11, which in the present case lies above the oscillating plate 15. Even if the suspension 17 is designed to be interrupted, the fluid moves only slightly back and forth in the half-space H, ie it is not exchanged and therefore does not “flow”, which leads to a reduction in possible impairments of the piezo actuator by the fluid.

FIG. 4 shows a schematic cross section through an embodiment with an axial suction opening. Most of the reference symbols have been used for reasons of clarity omitted. The embodiment shown differs from that of FIG. 3 in that the suction opening 24 does not run radially, but extends in the axial direction. Accordingly, it runs approximately parallel to the exit opening 25 and is located on an underside opposite the swing unit 10. The lengths of both openings 24, 25 can be the same, but also, as shown, different. The suction opening 24 can be in several parts, as shown in FIGS. 1 and 2. It can also be designed as a ring opening.

FIG. 5 shows an exploded view of a further embodiment of the micropump according to the invention. Here too, as in the following figures, most of the reference numerals have been omitted for reasons of clarity. FIG. 6 shows the embodiment of FIG. 5 in a sectional view. In contrast to the embodiment of FIGS. 1 and 2, a micropump according to this embodiment has a housing body 21, which is set up to accommodate all movable components, including the gap dimensions required for vibration. The housing cover 27 is essentially flat and, in particular, has no recesses for the internal components (swing unit 10) on the inside.

5 also shows an electrical connection 11B for the piezo actuator 11, which projects out of the housing 10 after it has been assembled (FIG. 6).

FIG. 7 and FIG. 8 show a further embodiment of the micropump. After this, the housing 20 is configured in two parts. It comprises a lower part 21A and an upper part 21B, envious parts can be connected to one another for example by means of gluing or welding. The connection preferably takes place in the course of the connection of the other housing components, such as, in particular, the cover 27. A two-part housing lower part 21 has the advantage that the suction openings 24 connect with the corresponding channels (only one provided with reference numerals) can be fluidically more favorable (see also the channels of FIGS. 1 and 2, in particular the 90-degree curve).

The embodiment of FIGS. 7 and 8 also shows a connector of the outlet opening 25 prepared for insertion into a hose.

LIST OF REFERENCE NUMBERS

10 swing unit

11 piezo actuator

11B electrical connection

12 vibrating membrane

13 blower chamber

14 ring

15 oscillating plate

16 blower opening

17 suspension

20 housing

21 housing body

21A lower part

21B top

22 recording

23 deepening

24 suction opening

25 exit opening

26 pumping chamber

27 housing cover

31.32 arrow

S gap

H space, half space

Claims

claims

1. A micropump for compressible fluids, comprising:

- A swing unit (10), this comprising a disk-shaped piezo actuator (11), which is arranged on a Schwingmemb ran (12), and an inner side of the vibration membrane (12) oppositely arranged swing plate (15) with a centrally arranged fan opening (16), and between the vibrating membrane (12) and vibrating plate (15) arranged, surrounding wall, so that a blower chamber (13) is formed;

- A housing (20) in which the swing unit (10) is completely receivable, and in which it is swingably mounted by means of at least one suspension (17), and which has a suction opening (24), and an outlet opening (25) which the fan opening (16) is opposite; the housing (20)

- A closed, also covering the piezo actuator (11) and thus protecting it from environmental influences, forms space (H), and

- At least one radially, or on one of the swing unit (10) opposite underside opening Ansaugöff (24) with an intake duct that leads into a between the oscillating plate (15) and the inside of the pump chamber (26), so that when the piezo actuator vibrates (11) the

Swing unit (10) can be set in vibration relative to the housing (20), whereby the compressible fluid through the

Suction opening (24) and through the outlet opening

(25) can be output.

2. Micropump according to claim 1, wherein the housing (20) one

Has housing body (21) and a housing cover (27), and the housing body (21) is set up to accommodate all movable components including the gap dimensions required for vibration.

3. Micropump according to claim 1, wherein the housing (20) one

Has housing body (21) and a housing cover (27), and at least parts of the movable components are arranged in an inner recess of the housing cover (27).

4. Micropump according to one of claims 1 to 3, wherein

Swing plate (15) and wall are made integrated.

5. Micropump according to one of claims 1 to 3, wherein

Vibrating plate (15) and wall are made as separate components.

6. Micropump according to one of the preceding claims, wherein the piezo actuator (11) is arranged gas-tight to the pump chamber (26).

7. Micropump according to one of the preceding claims, wherein the

Piezo actuator (11) with a diameter of 5 to 50 mm, and / or a gap (S) between the wall and the

Inside of the housing (20) less than 0.01 to 1 mm, and the micropump has a total height of 3 to 10 mm.

8. micropump according to one of the preceding claims, wherein the diameter of the blower opening (16) between 0.5 mm and 0.7 mm, and the diameter of the suction opening (s) (24) between 0.5 mm and 2.5 mm, and the diameter of the outlet openings (25) is between 0.7 and 0.9 mm.

9. A method of delivering a compressible fluid using a micropump as defined in any one of the preceding claims, wherein - In a suction phase, the piezo actuator (11) is controlled in such a way that it bulges against the direction of the blower opening (16), as a result of which a depression is formed in the blower chamber (13), which is formed by said blower opening (16) into the Pump chamber (26) propagates, whereby fluid is sucked through the suction opening (24), and

- In an output hare, the piezo actuator (11) is controlled such that it bulges in the direction of the blower opening (16) or goes into a flat rest position, as a result of which the negative pressure in the blower chamber (13) regresses or an excess pressure is generated, which also propagates through said fan opening (16) into the pump chamber (26), whereby fluid is dispensed through the outlet opening (25),

so that the swing unit (10) is set in vibration, the fluid being conveyed outside the half space (H) containing the piezo actuator (11).

10. The method according to claim 9, wherein the oscillating plate (15) also oscillates in the direction of movement of the piezo actuator (11).

11. The method according to claim 9, wherein the oscillating plate (15) oscillates against the direction of movement of the piezo actuator (11).