FLUID PUMP AND FORCE GENERATOR ARRANGEMENT WITH SUCH A FLUID PUMP

Abstract

A fluid pump for generating a fluid stream (55) is provided. The fluid pump includes a first actuator (20) with a first vibration element, a second actuator (30) with a second vibration element, and a power source that is connected to the first actuator and second actuator to supply energy to the first actuator and second actuator. The fluid pump further includes a controller that is connected to the power source and controls the power source to vary the energy supplied to the first actuator and second actuator. The first actuator (20) and the second actuator (30) are arranged opposite to each other so that a first movement direction of the first vibration element is inclined with respect to a second movement direction of the second vibration element. The controller controls the power source so that the first vibration element moves towards the second actuator and the second vibration element moves towards the first actuator in a synchronous manner and thereby cyclically soaks in a fluid from the surroundings and ejects the fluid in a directed manner.

Claims

1-15. (canceled)

16. A fluid pump for generating a fluid stream, comprising: a first actuator including a first vibration element; a second actuator including a second vibration element; a power source connected to the first and second actuators to supply energy to the first and second actuators; and a controller connected to the power source and configured to control the power source to vary the energy supplied to the first and second actuators, wherein the first and second actuators are arranged opposite to each other so that a first movement direction of the first vibration element is inclined with respect to a second movement direction of the second vibration element and wherein the controller is configured to control the power source so that the first vibration element moves towards the second actuator and the second vibration element moves towards the first actuator in a synchronous manner and thereby cyclically soaks in a fluid from the surroundings and ejects the fluid in a directed manner.

17. The fluid pump of claim 16, wherein the first and second actuators are arranged so that a volume between the first and second vibration elements is V-shaped and wherein a first opening of the volume is larger than a second opening that is arranged opposite to the first opening.

18. The fluid pump of claim 16, wherein the first and second actuators are selected from the group consisting of: a loudspeaker, a piezoelectric element, a hydraulic element connected to a piston, and a motor connected to the piston.

19. The fluid pump of claim 16, further comprising: a housing including at least two half-shells, wherein the first actuator is attached to a first half-shell of the at least two half-shells and the second actuator is attached to a second half-shell of the at least two half-shells.

20. The fluid pump of claim 19, wherein the housing defines one or more openings in a side wall that is arranged close to the first opening of the V-shaped volume.

21. The fluid pump of claim 20, wherein the housing includes guide walls arranged between the one or more openings of the housing and the first opening of the V-shaped volume and wherein the guide walls are arranged to guide a fluid flow that is ejected from the V-shaped volume.

22. The fluid pump of claim 21, wherein the guide walls are arranged in a jet-like manner tapering in a direction from the first opening of the V-shaped volume to the one of more openings of the housing.

23. The fluid pump of claim 16, wherein the first and second actuators are configured to be driven with an alternating voltage up to 1 kHz.

24. The fluid pump of claim 16, wherein the first and second actuators are configured to be driven with an alternating voltage up to 500 Hz.

25. A force generator arrangement, comprising: a first fluid pump; and a second fluid pump, wherein each of the first and second fluid pumps is a fluid pump of claim 16.

26. The force generator arrangement of claim 25, wherein the first and second fluid pumps are arranged so that the ejection direction of the fluid flow is substantially parallel.

27. The force generator arrangement of claim 25, wherein the first and second fluid pumps are inclined towards each other so that a first ejection direction of the first fluid pump and a second ejection direction of the second fluid pump intersect each other at a certain distance from the housing of the fluid pumps.

28. The force generator arrangement of claim 25, wherein the first and second fluid pumps are provided with control signals that have a phase shift with respect to one other.

29. The force generator arrangement of claim 25, wherein the first and second fluid pumps are connected to a fluid channel so that the first and second fluid pumps eject air into the fluid channel.

30. A fluid pump for generating a fluid stream, comprising: a first actuator including a first vibration element; a power source connected to the first actuator to supply energy to the first actuator; and a controller connected to the power source and configured to control the power source to vary the energy supplied to the first actuator, wherein the first actuator is arranged opposite to a side wall of a fluid chamber so that a first movement direction of the first vibration element is inclined with respect to the opposite side wall and wherein the controller is configured to control the power source so that the first vibration element moves towards the opposite side wall and thereby cyclically soaks in a fluid from the surroundings into the fluid chamber and ejects the fluid in a directed manner out of the fluid chamber.

31. The fluid pump of claim 30, wherein the first actuator and the opposite side wall are arranged so that a volume between the first vibration element and the second vibration element is V-shaped.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The fluid pump and the force generator arrangement will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:

[0050] FIG. 1 shows a schematic view of a part of a fluid pump;

[0051] FIG. 2 shows a schematic view of a fluid pump with first and second actuators;

[0052] FIG. 3 schematically shows first and second actuators of a fluid pump;

[0053] FIG. 4 shows a schematic representation of an actuator of a fluid pump;

[0054] FIG. 5 shows a schematic representation of first and second actuators of a fluid pump;

[0055] FIG. 6 shows a schematic representation of an actuator of a fluid pump;

[0056] FIG. 7 shows a schematic representation of a housing of a fluid pump;

[0057] FIG. 8 schematically shows the parts of a housing of a fluid pump;

[0058] FIG. 9 shows a schematic representation of first and second actuators of a fluid pump;

[0059] FIG. 10 shows a schematic representation of an actuator of a fluid pump;

[0060] FIG. 11 shows a force generator arrangement with two fluid pumps;

[0061] FIG. 12 schematically shows a force generator arrangement with two fluid pumps;

[0062] FIG. 13 schematically shows a force generator arrangement with multiple fluid pumps arranged in two groups opposite to each other.

DETAILED DESCRIPTION OF THE DRAWINGS

[0063] The following detailed description is merely exemplary in nature and is not intended to limit the invention and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0064] The representations and illustrations in the drawings are schematic and not to scale. Like numerals denote like elements.

[0065] A greater understanding of the described subject matter may be obtained through a review of the illustrations together with a review of the detailed description that follows.

[0066] FIG. 1 shows some parts of a fluid pump 10. The fluid pump 10 comprises a first actuator 20 and a second actuator 30 which are powered with electrical energy by a power source 40. The power source 40 is controlled by a controller 50.

[0067] Each actuator 20, 30 comprises a vibration element 21, 31. The vibration elements 21, 31 are configured to repeatedly move along a movement direction 22, 32, respectively. The vibration elements 21, 31 repeatedly carry out up and down movements. For example, the actuators 20, 30 are loudspeakers and the vibration elements 21, 31 are membranes or the respective loudspeaker.

[0068] The actuators are wired so that their movement is synchronized. That means that the vibration elements extend or push outwards at the same time and contract or pull inwards subsequently (after the outward movement) and at the same time.

[0069] FIG. 2 shows the fluid pump 10 with similar elements as already described with reference to FIG. 1. The first actuator 20 and the second actuator 30 are arranged opposite to each other so that each vibration element moves towards and away from the other actuator. The actuators 20, 30 are powered so that the respective vibration elements move towards each other at the same time and subsequently away from each other also at the same time, i.e., the movement of the vibration elements is synchronized. As a result of this movement, the space between the actuators and the vibration elements alternatingly becomes smaller (when the vibration elements of the opposite actuators move towards each other) and bigger (when the vibration elements of the opposite actuators move away from each other). This alternating movement of the vibration elements of the actuators generates a pumping effect that acts on a fluid (like air, other gases, or liquids) that is located between the vibration elements.

[0070] FIG. 3 shows two different configurations of a fluid pump with a different distance between the first actuator 20 (left side) and the second actuator 30 (right side).

[0071] When the airgap (i.e., distance between opposite actuators 20, 30) is small (e.g., 2 mm) in relation to the width and length of the speaker membrane (e.g., 23.5 mm 33.5 mm), then the air may have a challenge to escape in the desired direction. As a consequence, the major part of the air will escape from that one of the speaker sides (from the speaker center to the speaker side) that promises the lowest resistance to the outwardly moving air. Inhaling air will happen from all sides of the speaker.

[0072] FIG. 4 schematically shows a first actuator 20. The first actuator 20 comprises a vibration element 21 that is configured to move up and down along the movement direction 22. A force generator 25 is coupled with the vibration element 21 to cause the movement along direction 22. The vibration element 21 and the force generator 25 are located in a housing 23.

[0073] The force generator 25 may be an electric coil, a piezoelectric element, a hydraulic element, an electric motor, or the like. Generally, the force generator is typically driven with electric energy and generates a mechanical force based on said electric energy.

[0074] When the vibration element 21 moves along the direction 22 upwards, a working surface 24 of the vibration element acts on the fluid located at or on the vibration element and thereby causes the pumping effect.

[0075] FIG. 5 shows a side view of a fluid pump with a first actuator 20 and a second actuator 30 arranged opposite to each other and inclined with respect to each other so that an opening angle is defined for the space between the working surfaces 24, 34 of the respective vibration elements. The space between the working surfaces 24, 34 is V-shaped. When the working surfaces of the vibration elements move towards each other, the fluid between the working surfaces 24, 34 is pushed outward from the volume between the vibration elements. As the vibration elements are inclined with respect to each other, the major part of the fluid is pushed in the direction at which the opening angle 60 opens. This direction also defines the ejection direction of fluid flow 55.

[0076] The fluid pump with one or two actuators described herein creates a fluid flow because the vibration elements (e.g., membrane, working surface) are angled with respect to each other (i.e., not parallel) or with respect to the opposite side wall of the fluid chamber.

[0077] The amount of fluid per time pumped by the fluid pump (the amount of fluid per time corresponds to the generated force) can be determined by varying the amplitude and/or frequency of a power signal commanded by the controller 50 and supplied by the power source to the first and second actuators.

[0078] FIG. 6 shows a top view onto the first actuator 20 (lower actuator in FIG. 5). The first actuator 20 is located in a first half-shell 23A of the housing and the vibration element 21 moves substantially up and down out of the drawing layer. The first half-shell 23A defines openings 26A, 26B, 26C and guide walls 27A 27B located between the openings 26A, 26B, 26C. When the vibration element 21 moves upwards, it pushes fluid through the openings 26A, 26B, 26C. The guide walls 27A, 27B are arranged to guide the fluid flow when the fluid is ejected from the volume between the vibration elements.

[0079] FIG. 7 shows the housing 23 of a fluid pump. The housing comprises two half-shells 23A, 23B which are embraced by outer shells. The first and second half-shells 23A, 23B define the openings 26A, 26B, 26C and the guide walls 27A, 27B. Other mounting places are provided in the half-shells to mount the actuators therein. For example, a first actuator 20 is mounted in the first half-shell 23A, and a second actuator 30 is mounted in the second half-shell 23B.

[0080] On the right hand side in FIG. 7, the housing is shown in an assembled state. The first and second half-shells are embraced by outer shells and held in position. In this assembled state and with first and second actuators mounted to the housing, the fluid pump implements the principle described with reference to the preceding drawings. In particular, in the assembled state shown at the right hand side in FIG. 7, the first and second actuators are arranged as shown and described with reference to FIG. 5.

[0081] The half-shells of the housing may be produced by using 3D-printing techniques. The half-shells and the outer shells are exemplarily shown in FIG. 8. One guide wall may be printed to the first half-shell while the other guide wall is printed to the second half-shell. Of course, it is possible that both guide walls are printed to the same half-shell. Furthermore, the number of guide walls is not limited to the examples shown here. One, two or more guide walls may be used. However, when the half-shells are assembled, the guide walls adjoin the opposite half-shell so that the fluid pressed out of the volume between the actuators is guided by the guide walls along the openings defined by the guide walls and the half-shells.

[0082] FIG. 9 shows a fluid pump with a first actuator 20 and a second actuator 30. A volume 39 is defined between the working surfaces of the vibration elements of the respective actuators. The volume 39 is V-shaped, resulting from the fact that an opening angle 60 is defined between the working surfaces of the actuators, as described with reference to FIG. 5. A first opening 39A is defined on the left hand side of the volume 39, and a second opening 39B is defined on the right hand side of the volume 39. The first opening 39A is bigger than the second opening 39B. In one embodiment, the first opening is about 4 mm while the second opening 39B is 1 mm or even less.

[0083] FIG. 10 shows a top view of the first actuator 20 located in the housing 23. The vibration element may have a width of 30 mm. Guide walls 27A, 27B are located close to the vibration element and guide the fluid pushed aside by the vibration element through the first opening 39A (see FIG. 9) and define the ejection direction of the fluid flow 55. The outer opening of the guide walls 27A, 27B may have a width of 10 mm, i.e., one third of the width of the vibration element 21.

[0084] While certain dimensions are referred to in this example, it should be understood that those are not intended to limit the scope of the disclosure.

[0085] In certain embodiments, the vibration elements 21, 31 are non-symmetrical in shape, i.e., width and length are different, as can be seen in FIG. 10. The working surface may be rectangular or oval. In other embodiments, the working surface is symmetrical in shape. In this case, it may be beneficial that the working surface moves non-parallel and non-perpendicular to the side wall or to the opposite actuator.

[0086] In one embodiment, the fluid pump comprises an actuator with a working surface that is non-symmetrical in shape (i.e., it is oval or rectangular shaped), two membranes (two actuators) are placed opposite to each other, and the two actuators are angled in relation to each other. The angle between the two membranes (that are placed opposite to each other) depends on the membrane size (active surface area) and the achievable stroke (the larger the stroke, the larger the optimal angle will be.

[0087] When the membrane is longer than wide (non-symmetrical, see FIG. 10), then the gas will take the shortest distance possible to escape the squeezing-effect. Meaning that when the membrane is pushing outwards (in relation to the actuator itself, i.e., towards the opposite actuator) then the gas molecules placed in front of the membrane will move mainly to the left and the right side. However, when the membrane moves inwardly, gas is soaked in inwards (in relation to the actuator) from all sides (360? around the membrane).

[0088] When the wall opposite to the membrane is angled (or when the second membrane is angled) in relation to the first membrane, then the gas molecules will mainly move towards the side with the wider gap or with the shorter way (left/right in FIGS. 5, 6, 9, 10).

[0089] The actuators may be powered by a sinewave like signal (voltage or current), by a square signal (on-off), or something between (pseudo sine wave like shape). While the square (digital) like system provides more efficient results (more gas pumping for less energy), it is harsh on the membrane (creates more stress to the membrane). A sinus like signal may be less effective but also applies less mechanical stress to the membrane (longer product lifetime). This signal is commanded by the controller 50 and generated and provided by the power source 40 to the first and second actuators.

[0090] The signal frequency needed to drive such an actuator depends on the physical size of the membrane and its stroke and on the air pressure. The larger the air-pressure and the larger the surface area of a single membrane, the lower the operating frequency may be. Assuming that a single membrane has the size of a coffee cup sources (8 to 12 cm in diameter), the operating frequency is well below 100 Hz (near 10 Hz). When the actuator surface is about 4 cm.sup.2, for example, the operating frequency shifts towards 500 Hz or even near 1 kHz.

[0091] While certain embodiments have been described with two actuators being arranged opposite to each other, it is noted that the principle of the fluid pump will also work with only one actuator when a wall (for example of a housing) is arranged opposite to the single actuator, and the single actuator and the wall are inclined towards each other so that the moving direction of the vibration element is non perpendicular with respect to the wall. In that case, the volume between the wall and the working surface of the single actuators is also V-shaped so that the same principle applies as described with reference to FIG. 5 and FIG. 9, for example.

[0092] FIG. 11 shows a force generator arrangement with two fluid pumps 10A, 10B. While the fluid pumps 10A, 10B are only schematically shown here, it is understood that the fluid pumps include the elements that are required to implement the pumping effect as described herein.

[0093] Each fluid pump 10A, 10B works in accordance with the principles described herein and generates a repelling force by pumping a fluid out of the openings of the fluid pump housings. By using multiple fluid pumps, the amount of the generated force is increased.

[0094] The fluid pumps may be oriented in different directions. In that case, the individual fluid pumps may be controlled individually to generate a repelling force and the resulting direction in which the force generator arrangement is moved can be determined. For example, four fluid pumps may be coupled to each other in a manner that each fluid pump has an ejection direction of the fluid flow in four different directions 90? different from each other (left, right, back, forth). Depending on which fluid pump is powered at what intensity, the direction of the resulting force can be determined freely as desired.

[0095] FIG. 12 shows two fluid pumps 10A, 10B with ejection directions 55A, 55B pointing towards each other. The fluid flows ejected by the two fluid pumps 10A, 10B superpose after being ejected by the fluid pumps and, therefore, generate a higher propulsion force.

[0096] FIG. 13 shows a force generator module with two identical fluid pump arrays, each of which includes four fluid pumps 10A, 10B, 10C, 10D. The fluid pumps of one array are coupled so that the ejected fluid flow of each fluid pump enters a fluid channel 70 which guides the sum of all fluid flows generated by the fluid pumps of one fluid pump array.

[0097] In this embodiment, the fluid pumps may be powered consecutive in a predetermined order so that one or more fluid pumps eject fluid while one or more other fluid pumps soak in fluid for the next cycle. Thus, a continuous fluid flow is ejected from the fluid channel 70. The fluid pumps of the two fluid pump arrays may be controlled so that any noise generated by the loudspeakers is cancelled by the loudspeakers of the other fluid pump. This can be done by powering the first fluid pump array with a first control signal and the second fluid pump array by a second control signal which corresponds to the inverted first control signal.

[0098] While certain examples are described with reference to loudspeakers, it is understood that other actuators may be used, e.g., piezoelectric elements, to implement the same principle as described with reference to loudspeakers.

[0099] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It will be understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the claims.

[0100] Additionally, it is noted that comprising or including does not exclude any other elements or steps and a or an does not exclude a multitude or plurality. It is further noted that features or steps which are described with reference to one of the above exemplary embodiments may also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims are not to be construed as a limitation.

LIST OF REFERENCE SIGNS

[0101] 10 fluid pump, preferably for pumping gaseous fluids [0102] 20 first actuator (loudspeaker, piezoelectric element) [0103] 21 vibration element [0104] 22 movement direction [0105] 23 housing [0106] 23A first half-shell [0107] 23B second half-shell [0108] 24 working surface [0109] 25 force generator (electric coil, piezoelectric element, hydraulic element, motor) [0110] 26A-26C opening [0111] 27A, 27B guide wall [0112] 30 second actuator [0113] 31 vibration element [0114] 32 movement direction [0115] 39 volume between the vibration elements [0116] 39A first opening [0117] 39B second opening [0118] 40 power source [0119] 50 controller [0120] 55 ejection direction of fluid flow [0121] 60 opening angle [0122] 70 fluid channel