EP2010784B1 - Pump element and pump comprising such a pump element - Google Patents

Abstract

A pump element includes a pump element housing defining a pump chamber having an inlet and an outlet, and at least a first movable element movable in the pump chamber between a first and a second position. During a movement of the first movable element in the direction from the first to the second position, a flow resistance of a flow path from the first movable element through the inlet is larger than a flow resistance of a flow path between the pump element housing and the first movable element. During a movement of the first movable element in the direction from the second position to the first position, a flow resistance of a flow path from the first movable element through the outlet is smaller than a flow resistance of the flow path between the pump element housing and the first movable element. Thus, during a reciprocating movement of the first movable element between the first and the second position, a net flow through the outlet takes place.

Description

The present invention relates to a pumping element and a pump having such a pumping element.

In the prior art, a variety of pumps are known which can be used to drive fluids. The sizes of the pumps vary from microfabricated to very large pumps with high pump power, for example, in power plants.

Pumps according to the state of the art are complex structures which contain the fluidic structure, the drive and optionally a control or regulating device. A disadvantage of the high complexity of the known pumps are the high production costs, which almost preclude the use of such pumps for single use. Furthermore, in complex structures, the effort to achieve a high reliability increases.

In many pumps also auxiliary materials such as lubricating oils or greases for the drive or the operation of the pump are necessary, which could also come into contact with the fluid. This prohibits use in medical or process applications.

From the AT 283 121 B is a fuel piston pump with a Pampelement, as defined in the preamble of patent claim 1 is known, which has a pressure valve and a slot control on the suction side and a reciprocating piston. The piston carries at one end a magnet armature and its piston rod is arranged in a cylinder within a magnetic coil.

There is therefore a need for a pumping element and a pump which, inter alia, in medical and procedural Applications and consumer applications can also be used as disposable applications.

According to the invention this need is solved by a pumping element according to claim 1 and a pump with a corresponding pumping element according to claim 9.

Thus, in embodiments of the present invention, upon movement of the movable member in the direction from the first to the second position, more fluid is forced past the first movable member toward the outlet of the pumping chamber than leaves the pumping chamber through the inlet. In embodiments of the invention, the inlet may be closed during the movement of the first movable element in the direction from the first to the second position, or at least during a majority of this movement, for example by a second movable element.

In embodiments of the invention, moreover, due to the defined flow resistances upon movement of the first movable member in the direction from the second position to the first position, more fluid is expelled through the drain than is moved past the movable member toward the inlet. Thus, by a reciprocating motion of the movable member, a net flow through the drain can take place.

• einem zweiten beweglichen Element, das in der Pumpkammer zwischen einer dritten und einer vierten Position bewegbar ist;
• einer ersten Feder, die das erste bewegliche Element in die erste Position vorspannt; und
• einer zweiten Feder, die das zweite bewegliche Element in die dritte Position vorspannt,
• wobei bei einer Hin- und Her-Bewegung des ersten beweglichen Elements zwischen der ersten und zweiten Position und des zweiten beweglichen Elements zwischen der dritten und
• vierten Position ein Nettofluss durch den Ablauf stattfindet.

Embodiments of the present invention provide a pumping element further comprising:

• a second movable member which is movable in the pumping chamber between a third and a fourth position;
• a first spring biasing the first movable member to the first position; and
• a second spring that biases the second movable member to the third position,
• wherein in a reciprocating movement of the first movable member between the first and second position and the second movable member between the third and
• fourth position, a net flow through the expiration takes place.

In embodiments of the invention, a pump may include a respective pumping element and a drive unit configured to drive the first movable element from the first to the second position and / or to drive the second movable element from the third to the fourth position ,

Embodiments of the present invention may relate to miniature pumps or micropumps in which a quantity of fluid pumped per pump stroke is in the microliter range, nanoliter range, or picoliter range. Embodiments of the invention may relate to pumping elements or pumps for liquids, for example, infusion solutions, lubricants, foods or cleaning agents, wherein the pumping element and drive unit may be designed separately. The pumping element can be produced inexpensively, for example, by plastic injection molding and disposed of after use. The drive unit may be reused, in embodiments of the present invention when pumping the drive unit is not in contact with the fluid to be pumped. In embodiments of the invention, a quantity of fluid pumped can be determined directly from the number of pump strokes. Furthermore, in embodiments of the invention, the pumping element may have an integrated check valve for controlling the fluid flow. In embodiments of the invention, the integrated check valve can block fluid flow through the pump element in the non-actuated state of the pump element.

Embodiments of the pump according to the invention can be used for a variety of applications, in particular in the fields of medicine, process engineering and research. An example of this are automatic medicament dosage devices in human medicine.

In embodiments of the present invention, upon movement of the first movable member in the direction from the first to the second position, fluid transport from an out-of-drain side of the first movable member past the movable member into a downstream side the first movable element arranged area instead. During this movement, the inlet can be closed in order to be able to realize the lowest possible return flow through the inlet and an associated suction through the outlet. During the movement of the first movable element in the direction from the first to the second position, fluid, for example a liquid or a gas, can thus be transported past the first movable element.

In embodiments of the present invention, upon movement of the first movable member in the direction from the second position to the first position, fluid to be pumped is displaced by the first movable member and discharged through the drain. At the same time fluid is sucked through the inlet. This movement phase can thus be referred to as transport phase. As a result of alternating transport phases and pumping phases, a net flow can thus take place in the direction from the inlet to the outlet.

In embodiments of the present invention, the pumping element may be configured such that upon actuation, the second movable element is moved faster from the third to the fourth position than the first element is moved from the first to the second position. In embodiments of the present invention, the second movable element in the fourth position closes the inlet. Thus, during the phase in which fluid to be pumped is transported past the first movable element, backflow through the inlet can be reduced or minimized. In embodiments of the present invention, the second spring may have a lower spring constant than the first spring to cause the faster movement of the second movable member. In embodiments of the invention, separate drive devices may be provided for the first movable element and the second movable element. A driving device for the second movable member may cause movement thereof from the third position to the fourth position before a driving device causes the movement of the first movable member from the first to the second position. In alternative embodiments, the drive unit and / or the first moveable element and the second moveable element may be configured to exert a greater force on the second moveable element to move faster to the fourth position than the first moveable element in FIG the second position is moved.

Embodiments of the present invention enable the fluidic structure of the pumping element and its drive to be constructed separately from each other. The actual pumping element may consist of a few components and can be produced, for example, inexpensively by plastic injection molding. Embodiments of the present invention allow the pumping element to be disposed of after use so that disposable applications are economically possible. In embodiments of the invention, however, the more expensive drive unit, which may include a controller, may be used for multiple pumping elements or over multiple pumping element life cycles. As a result, in critical applications, such as medical technology or food technology, after each application, the pumping element, that is, the fluidic element that comes into contact with the fluid to be pumped, be replaced without having to replace the more expensive drive unit.

In embodiments of the present invention, a pumping function may be performed by two metallic moving elements, for example balls or pistons, which are held in a defined position in a pumping chamber, which may also be referred to as a channel, by two springs. In a first or third position, the first movable member closes the drain from the pumping chamber, while the second movable member can release the inlet to the pumping chamber, which may be connected to a reservoir for a fluid to be pumped, the pumping chamber through the Inlet is filled with the fluid. In embodiments of the invention, by one or more integrated in the drive unit coils, the movable elements can be moved by a magnetic force against the spring force in the second and fourth position. In this case, in embodiments, the second movable element first closes the inlet, while the first movable element releases the drain and the fluid, liquid or gas contained in the pumping chamber is pushed past the first movable element (transport phase). After switching off the magnetic force, the spring pushes back the first movable element, whereby fluid located in front of the first movable element is at least partially conveyed through the backflow. A leakage current arises through the gap between the movable element and the pressure chamber wall through which a certain amount of liquid can flow back during the pumping movement. The magnitude of the leakage current is determined by the gap width between the first movable element and the pumping chamber wall, ie the flow resistance of the flow path between the first movable element and the pumping chamber wall. At the end of the pumping movement seals in embodiments of the invention, the first movable element from the process again. The second movable element opens in embodiments of the invention, approximately at the same time the inlet, whereby the housing refills. About number and speed of Pump strokes can be controlled while the metered flow. In addition, between pump cycles, the pump can block fluid flow without leakage.

In embodiments of the invention pumping elements with different flow rates can be realized by the pump design. For example, in this regard, the cross section of the fluidic structure, i. the pumping chamber channel thereof, the length of the pumping stroke and the size of the gap between the movable member and the channel wall are adjusted to adjust the amount of fluid delivered per pump stroke. Thus, it is possible, for example, with one or a few different drive units to cover a large range of flow rates. For example, pumping elements with different flow rates can be driven with the same drive unit.

Embodiments of the present invention also advantageously allow a pump to be implemented without much overhead with a monitoring device that can check the position of the pump, i. which can determine the position of the first movable element and / or, if present, the position of the second movable element. In embodiments of the invention, the drive unit may comprise a drive coil, wherein in the drive unit, a further measuring coil can be integrated. By generating a superimposed alternating magnetic field through the drive coil, a voltage in the additional measuring coil can be induced. The induced voltage is dependent on the position of the movable element (s) whose material has a permeability. Thus, the position of the pumping element can be determined by a suitable measuring device, whereby a function monitoring of the pump is made possible.

Fig. 1a und 1b

schematische Schnittdarstellungen eines Aus- führungsbeispiels einer erfindungsgemäßen Pumpe;

Fig. 2 und 3

schematische Querschnittdarstellungen von Ausführungsbeispielen zur Erläuterung eines Strö- mungswegs zwischen Pumpelementgehäusen und ersten beweglichen Elementen;

Fig. 4 und 5

schematische Darstellungen von Ausführungs- beispielen, die einen variablen Flusswiderstand des Strömungswegs zwischen einem Pumpelementgehäuse und einem ersten beweglichen Element ermöglichen.

Fig. 6a und Fig. 6b

schematische Schnittdarstellungen zur Erläuterung eines weiteren Ausführungsbeispiels ei- ner erfindungsgemäßen Pumpe;

Fig. 7 bis 9

schematische Schnittdarstellungen weiterer Ausführungsbeispiele erfindungsgemäßer Pumpen; und

Fig. 10

eine schematische Schnittdarstellung eines Ausfüh- rungsbeispiels eines erfindungsgemäßen Pumpele- ments.

Embodiments of the present application are explained below with reference to the accompanying drawings. Show it:

Fig. 1a and 1b

schematic sectional views of an embodiment of a pump according to the invention;

FIGS. 2 and 3

schematic cross-sectional views of embodiments for explaining a flow path between pumping element housings and first movable elements;

4 and 5

schematic representations of exemplary embodiments that allow a variable flow resistance of the flow path between a pump element housing and a first movable member.

Fig. 6a and Fig. 6b

schematic sectional views for explaining a further embodiment of a pump according to the invention;

Fig. 7 to 9

schematic sectional views of further embodiments of pumps according to the invention; and

Fig. 10

a schematic sectional view of an exemplary embodiment of a pumping element according to the invention.

In the various representations, the same reference numerals are used for the same or functionally equivalent elements, wherein a repeated description of corresponding elements is omitted.

Fig. 1a shows a sectional view of an embodiment of a pump according to the invention in a resting state and Fig. 1b shows the pump in an actuated state. The pump comprises a pumping element 10 and a drive unit 12. The pumping element 10 comprises a pumping element housing 14 and the drive unit 12 comprises a drive unit housing 16. The pumping element housing 14 and the drive unit housing 16 are constructed as separate housings. such that they can be coupled together and separated from each other. Suitable devices by means of which the drive unit housing 16 can be reversibly coupled to the pump element housing 14 will be apparent to those skilled in the art and include, for example, snap connections, threaded connections, hooks, clips, hook and loop fasteners, and the like, and need no further explanation herein.

The pumping element housing 14 defines a pumping chamber 18, an inlet 20 and a drain 22. The pumping element housing 14 can be realized inexpensively, for example, by plastic injection molding, whereby the inlet 20 and the outlet 22 can be injection-molded. In the pumping chamber 18 is a first ball 24, which constitutes a first movable element, and a second ball 26, which constitutes a second movable element. Between the balls 24 and 26 is a spring 28. Between the second ball 26 and the pump element housing 14 is a second spring 30. By the first spring 28 and the second spring 30, the first ball 24 and the second ball 26 in the in Fig. 1a biased positions shown. In the embodiment shown, the springs 28 and 30 are formed as spiral springs.

In the illustrated embodiment, without an external force, the first ball 24 is positioned by the spring assembly such that the drain 22 is closed with the first ball 24 held in that position by the first spring 28. The second ball 26 is positioned by the spring arrangement so that the inlet 20 is opened and the pumping chamber 18 is filled in the housing 14 with fluid or is.

The inlet 20 may be connected via suitable fluid lines to a fluid reservoir (not shown), while the outlet 22 may be connected via suitable fluid lines to a target area (not shown). To this end For example, the inlet 20 and the drain 22 may include luer connector structures 32, for example.

To increase the sealing effect of the first ball 24 on the drain 22, a further spring 34 may be provided, for example in the form of a leaf spring, which presses the first ball 24 onto a sealing seat formed by the drain 22. In the embodiment shown, the leaf spring 34 generates a force perpendicular to the force generated by the springs 28 and 30. The balls 12 may be formed, for example, as metallic balls, while the springs may be performed, for example, non-magnetic non-ferrous metal.

The drive unit 12 comprises one or more drive coils 40 as an electromagnetic drive for the metallic ball 24, which surround a ferromagnetic core 42. In order to increase the magnetic force on the movable members, the ferromagnetic core 42 may also be in the form of a yoke with suitable pole pieces at the positions of the movable members, thereby greatly improving the magnetic flux as later referred to Fig. 5 to 7 is explained in more detail. The drive unit 12 further includes a controller 44 coupled to the drive coil (s) 40 for selectively and cyclically impressing current through the one or more coils 40 to thereby generate an electromagnetic force acting on the metallic balls 24 and 26 ,

erforderlich.Due to the generated electromagnetic force, the second ball 26 is moved against the force of the second spring 30 in the direction of the inlet 20, so that the inlet 20 is sealed, as in Fig. 1b is shown. By increasing the current through the drive coil (s) 40, the magnetic force on the ball 24 can be increased as long as the ferromagnetic core 42 and, if present, a yoke are not yet in the magnetic field Saturation is located. To the second ball 26 from the rest position, the in Fig. 1a is shown in the sealing position, in Fig. 1b is shown to move, this must be moved by a distance s ₂ . For this a magnetic force F _magnet (s ₂ ) is necessary. The bias of the springs F _before can be adjusted so that the first ball 24 does not move until the second ball 26 has sealed the inlet 20. Finally, the first ball 24 against the force of the first spring 28 with the spring constant c ₁ in the position in Fig. 1b is shown, this must be moved by a distance s ₁ . To overcome the spring forces for at least one magnetic force of $${\mathrm{F}}_{\mathrm{magnet}}\left({\mathrm{s}}_{\mathrm{1}}\right)\mathrm{=}{\mathrm{F}}_{\mathrm{magnet}}\left({\mathrm{s}}_{\mathrm{2}}\right)\mathrm{+}{\mathrm{c}}_{\mathrm{1}}\mathrm{*}{\mathrm{s}}_{\mathrm{1}}\mathrm{+}{\mathrm{F}}_{\mathrm{flow}}\left[\mathrm{N}\right]$$

required.

In this case, the outlet 22 is opened and the fluid flows laterally during the movement of the second ball 24 past the latter, ie flows through a flow path between the first ball 24 and the pump element housing 14. The flow force F _flow essentially depends on the gap width of the gap the second ball 24 and the pump element housing 14 and from the speed v at which the first ball 24 moves.

To describe the functionality of the Fig. 1a and 1b Thus, the spring rates and spring preloads of the springs 14 and 17 may preferably be selected so that after the magnetic force is turned on, the ball 26 first moves and seals the inlet 20 before the ball 24 moves through the fluid and releases the drain 22 , If the magnetic force is turned off, then both balls can move virtually simultaneously, inter alia, because the spring 30 is supported by the inflowing through the inlet 20 fluid. The second ball 26 may have a slightly smaller diameter than the first ball 24.

Fig. 2 shows schematically a cross-sectional view along the line II-II in FIG Fig. 1b wherein a corresponding annular gap 46 is shown similar to a technical fit, which provides the flow path between the first ball 24 and the inner pumping chamber wall in a pumping chamber having a circular inner cross section. As a result, the ball has a lateral play in the pumping chamber, through which the flow gap results. The gap width of the annular gap can preferably be significantly smaller than the diameter and depend on the diameter of the ball. For example, depending on the diameter of the sphere, the gap width may be less than 100 μm, less than 50 μm or less than 20 μm. In Fig. 2 the ball is shown centered, wherein actually the position may differ from the position shown depending on the circumstances, that is, for example, the orientation, so that no gap is arranged on one side of the ball.

Alternatively, another internal cross section, for example a square inner cross section, could also be used. A schematic cross-sectional view of an alternative embodiment with a pump element housing 14a, which has a round pump chamber cross-section, is shown in FIG Fig. 3 shown. A cylinder-piston-shaped movable element 24a in this case has one or more channels 46a, which result in one or more flow paths between the movable element 24a and the pump element housing 14a, as in FIG Fig. 3 can be seen. Although in Fig. 3 four channels 46a are shown, in alternative embodiments a different number of channels, for example only one channel, may be provided.

Returning to Fig. 1b this shows the arrangement of the pump under the action of a magnetic force of F _magnet ≥ F _magnet (s ₁ ). The control device 44 is designed to supply the drive coil 40 with such a current that a corresponding magnetic force is exerted on the first ball 24.

By an actuation of the drive unit 12 is thus a movement of the balls 24 and 26 from the positions in Fig. 1a are shown in the positions in Fig. 1b are shown causes. In this case, the ball 24 is moved away from the outlet 22 in the pumping chamber 18, whereby fluid is transported from a side of the ball 24 facing away from the outlet 22 to a side of the ball facing the outlet 22, along the flow path 46 or 46a. as in the example FIGS. 2 and 3 are shown. Now, if the magnetic force is switched off by the drive unit 12 by the controller 44, the current through the drive coil 40, pushes the ball 24 due to the force of the first spring 28, the fluid from the pumping chamber 18 through the drain 22 addition, whereupon the ball 24th Finally, the drain 22 seals again. During this movement of the ball 24, the second ball 26 releases the inlet 20, so that again new fluid can flow through the inlet 20 into the pumping chamber. Thus, the balls 24 and 26 take by the bias of the springs 28 and 30 again in Fig. 1a positions shown. Starting from this state, the drive unit can then be actuated again, so that a defined volume of fluid can be pumped by a cyclical actuation of the drive unit by carrying out a specific number of pump cycles per known stroke per pump stroke.

The volume pumped is given by the geometry, in particular the size of the ball 24, the size of the pumping stroke (ie the distance s _{1 of} the movement of the ball 24) and the size of the flow gap 46 between the ball 24 and the pumping element housing 14. By adjusting The geometry can therefore be adjusted, the volume pumped per pump stroke. Based on the number of pump strokes, the volume delivered can be determined.

For the achievable dosing accuracy of the pump, it is advantageous in embodiments of the invention that the Ratio between the pumped amount of fluid, for example, amount of liquid and the amount of fluid flowing back through the gap 46 during the pumping movement of the ball 24 is as large as possible.

For this purpose, in embodiments of the invention, the flow resistance of the gap 46 during the pumping movement be sufficiently large. This can be achieved by a correspondingly narrow gap 46 or additional measures. In this regard shows Fig. 4 a schematic representation of a pump element housing 14b, in which a movable member 24b is arranged. The cross-section of a pump chamber 18a formed in the pumping element housing 14b may, for example, be circular, wherein the movable element 24b may be cylinder-piston-shaped, so that a flow gap 46b is formed between the inner wall of the pump element housing 14b and the movable element 24b. The movable member 24b has a seal member 50 fixed thereto and changing a flow resistance for a fluid to be pumped between the movable member 24b and the passage wall of the pump chamber housing 14b depending on the direction of movement.

The sealing element 50 is designed as a limp and is suitable, for example, to be connected only via a pin 52 with the movable element 24b. The sealing element 50 thus provides in a movement of the movable element 24 b in Fig. 4 to the right for a fluid flowing past a lower flow resistance than in a movement of the movable element 24b in Fig. 4 to the left. In other words, the seal member provides greater flexibility in moving to the right as it can be deflected away from the movable member 24b while being pushed leftward against the same upon movement of the movable member 24b. Thus, the movable element here has an additional valve function.

The additional sealing element 50 can be made of any elastic material, for example rubber, which changes its fluidically effective geometry depending on the direction of movement of the movable element 24b and thus allows a change in the flow resistance in order to be able to produce a desired valve function in this way.

An alternative embodiment for achieving a dynamic valve action of a movable element is shown in FIG Fig. 5 shown schematically. Fig. 5 again schematically shows a pumping element housing 14c and a movable element 24c disposed therein. Furthermore, in Fig. 5 shown pole pieces 56 and 58 of a magnetic drive unit. The movable member 24 c is in the in Fig. 5 shown embodiment, in dependence on its position and position in the flow channel, ie in the pumping element housing 14c formed in the pumping channel 18b, causes a different flow resistance of a fluidic gap 46c. In the embodiment shown, this can be achieved by superimposing a translatory movement 60 of the movable element 24c through a rotational movement, by means of which the fluidic gap 46c increases or decreases, so that different flow resistances are produced. At the in Fig. 5 For example, the element 24c may be, for example, a ball flattened on two or more sides, which may rotate about its central axis. Further, the movable member 24 c may be made of a permanent magnetic material, so that a rotation of the movable member 24 c takes place when it is moved by the translational movement 60 between the pole pieces 56 and 58, as indicated by dashed lines in Fig. 5 is indicated. Advantageously, the cross-section of the gap 46c may decrease during the pumping movement of the movable member 46c toward the pump outlet and increase during the loading movement in the direction away from the pump outlet, whereby a dynamic valve action can be achieved.

The Fig. 6a and 6b show a further embodiment of a pump according to the invention, a modification of the in the Fig. 1a and 1b illustrated embodiment, with an explanation and description of the already reference to the Fig. 1a and 1b described elements and functionalities is omitted.

That in the Fig. 6a and 6b shown pumping element completely corresponds to that of the embodiment of Fig. 1a and 1b , in which Fig. 6a in turn, the two balls 24 and 26 at rest and Fig. 6b shows the two balls in the actuated state. In the in the Fig. 6a and 6b As shown, a drive unit 12a differs from the reference to FIGS Fig. 1a and 1b described embodiments in that a detection device is provided for determining a position of the balls. This detection device comprises a detection coil 70 and a detection device 72. In this case, the detection device 72 can be integrated in the control device 44 or can be provided separately therefrom. The detection device 72 is coupled to the detection coil 70 and may be further coupled to the drive coil 40. Either the control device 44 or the detection device 72 are designed to send such a changing current through the drive coil 40 that a changing magnetic field, for example an alternating magnetic field, is superimposed, the change of which induces a voltage U _ind in the detection coil 70. Due to the permeability of the material of the balls 24 and 26, this voltage also changes depending on the position of the balls in the pumping element. The detection device 72 is designed to detect the voltage U _ind and to evaluate changes thereof in order to draw conclusions about the position of the balls in the pump element. Thus, the position of the balls 24 and 26 within the pumping element can be 10 so that the position and function of the pumping element can be monitored. In such an embodiment, it is again possible to amplify the measurement signal which is represented by the voltage induced in the coil 70 by means of a magnetic yoke in the form of a yoke and pole shoes positioned thereon.

Exemplary embodiments of arrangements which enable an increase in the effective magnetic forces or a gain of the measurement signal will be described below with reference to FIGS Fig. 7 to 9 explained in more detail.

The Fig. 7 to 8 each show a pumping element having a pumping element housing 80 in which a pumping chamber 82, an inlet 84 and a drain 86 are formed. In the pumping chamber 82, a first movable ball 88 and a second movable ball 90 are arranged, which are biased by a first spring 92 and a second spring 94 in the positions shown.

At the in Fig. 7 In the embodiment shown, two separate drive units 102a and 102b are provided for the first ball 88 and the second ball 90. The drive units 102a and 102b may have a similar construction, wherein respective features of the drive unit 102a are marked with the letter "a", while features of the drive unit 102b are marked with the letter "b". The drive units have drive unit housing parts 104a and 104b, which can be reversibly coupled to the pumping element. The drive unit 102a has one or more drive coils 106a and one or more sense coils 108a. The drive unit 102b has one or more drive coils 106b. The drive unit 102a has a control device 44a and a detection device 72. The drive unit 102b also has a control device 44b and can optionally furthermore also comprise one or more detection coils and a detection device.

As in Fig. 7 As can be seen, the drive coils 106a and 108a are wound around a ferromagnetic yoke 110a, and the drive coils 106b are wound around a ferromagnetic yoke 110b. Pole shoes 112a and 114a, which guide the magnetic flux such that the ball 88 is pulled between the pole pieces 112a and 112b when actuated, are attached to the ferromagnetic yoke 110a. Pole shoes 112b and 114b are also attached to the yoke 110b, which guide the magnetic flux such that in the actuated state the ball 90 is pulled between the pole shoes 112b and 114b.

Through the use of yokes and pole shoes, which may for example consist of a ferromagnetic material, the movable elements, in the illustrated embodiments, balls 88 and 90 become part of the magnetic circuit, whereby the acting magnetic forces can be significantly larger. Furthermore, the measurement signal induced in the detection coil 108a and detected by the detection device 72 can thereby be significantly stronger.

The structural design of the yokes and pole shoes depends on the particular design of the pumping element. It should be noted at this point that the geometric configuration of the pumping elements shown in the exemplary embodiments is purely exemplary for illustrative purposes. It should also be noted that the inlets and outlets can be arranged at a suitable position, wherein in particular the position of the inlet into the FIGS. 7 and 8 is purely schematic and of course at a suitable location to allow a flow of a fluid, ie a liquid or a gas, into the pumping chamber.

The functionality of in Fig. 7 The embodiment shown may substantially correspond to the functionality of the above with reference to FIGS Fig. 1a and 1b correspond to described embodiment. In this regard, the spring constants of the springs 92 and 94, the timing of impressing a current into the drive coils 106a and 106b and / or the magnitude of the current impressed into the drive coils 106a and 106b (and the magnetic field generated thereby) may be adjusted to effect in that, when actuated, the ball 90 closes the inlet 84 before the ball 88 is moved from the position shown to the actuated position.

Fig. 8 shows a schematic view of an embodiment in which a common drive unit for the first ball 88 and the second ball 90 is provided. The drive unit 120 has a drive unit housing 122, which in turn is reversibly coupled to the pumping element. The drive unit further comprises a control device 44 and a detection device 72 which, in analogy to the above descriptions, are coupled to one or more drive coils 106 and one or more detection coils 108. The drive coil 106 and the detection coil 108 are wound around a yoke 110, which may be made of a ferromagnetic material, as shown. The yoke 110 has first pole shoes 124 and 126 for guiding the magnetic flux for actuating the first ball 88 and second pole shoes 128 and 130 for conducting the magnetic flux for actuating the second ball 90.

Regarding the functionality of in Fig. 8 shown embodiment can be made to the above statements with respect to Fig. 1a, 1b . 6a and 6b can be referenced, in turn, through the yoke 110 and attached to the same pole pieces, a gain of the magnetic force and the measurement signal can be achieved.

An alternative embodiment of a drive unit 140 for actuating both balls 88 and 90 is shown in FIG Fig. 9 shown. The drive unit 140 comprises a drive unit housing 142, in which in turn a control device 44, a detection device 72, one or more drive coils 106 and one or more detection coils 108 are arranged. Like the in Fig. 9 shown embodiments, in this embodiment, the drive coil 106 and the detection coil 108 on a yoke 144 which is arranged between pole pieces 124, 126, 128 and 130, is provided. This in Fig. 9 shown embodiment therefore allows a very compact design of the drive unit, which in turn is reversibly coupled to the pump element housing.

Fig. 10 shows a pumping element 150 according to an alternative embodiment. The pumping element 150 comprises a pumping element housing 152 in which in turn a pumping chamber 154, an inlet 156 and a drain 158 are formed. The pumping element 150 further includes a first ball 160, a second ball 162, a first spring 164 and a second spring 166. Between the springs, a spring stop 168 is arranged. The springs 164 and 166 bias the balls 160 and 162 to the position shown in FIG Fig. 10 is shown before.

Using a corresponding drive unit (not shown), the ball 160 may be moved away from the drain 158 against the force of the spring 164 to open it and to transport fluid past it while the inlet 156 is closed by the ball 162 , In order to realize a corresponding drive unit, for example, pole shoes can in turn be displaced somewhat from the ball 160 in the direction of the inlet 156.

After switching off the magnetic force, the spring 164 drives the ball back to the position in Fig. 10 shown, wherein fluid is driven from the drain 158. The ball 162 forms together with the spring 166 while a check valve, which allows running of fluid through the inlet 156. The spring 166, the ball 162 and the sealing seat on the inlet 156 can be coordinated so that the check valve thus formed immediately opens in the direction of passage when the ball 160 is in the pumping movement to the outlet 158 out, and in the reverse direction immediately closes when the ball 160 is in the loading motion away from the drain 158.

At the in Fig. 10 In the embodiment shown, the spring 164 together with the ball 160 thus forms the pump drive, wherein the spring 164 and the sealing seat of the ball 160 and the pump housing 152 and the outlet 158 can be tuned by the same so that the outlet 158 through the element 160 is reliably sealed, as long as the magnetic drive is switched off, ie as long as the system is at rest. As a result of this structure, a quiescent flow from the inlet 156 through the outlet 158 can likewise be effectively excluded, as can a return flow from the outlet 158 back to the inlet 156.

In the embodiment according to Fig. 10 the springs 164 and 166 are decoupled and are based on a fixed stop 168 from. The two spring forces are determined solely by the distance between the ball 160 and the spring stop 168 or between the ball 162 and the spring stop 168 and are thus completely decoupled from each other.

In support of the opening of the inlet 156, when the ball 160 is in the pumping motion toward the drain 158, an additional magnetic drive could be provided for the ball 162 which is controllable independently of the magnetic drive for the ball 160.

In summary, embodiments of the present invention thus provide a pump for fluids having a first one Housing and with an inlet and a drain and a second housing, which can be mechanically connected to the first housing detachably. The first housing may include a first movable member and at least one first spring, the first spring defining the first movable member in a position that seals the drain. The housing may include a second movable member and at least one second spring, the second spring defining the second movable member in a position that releases the inlet. The second housing may include at least one coil, a ferromagnetic core, and a controller for generating a magnetic field and thereby defining the movable members against the acting force of the springs in a second position, the inlet being sealed by the second movable member and the flow is released by the first movable element. After switching off the magnetic force, the movable elements can be returned to the rest position by the springs so that fluid contained in the first housing is at least partially conveyed out of the drain.

Embodiments of the present application comprise, as described above, two movable elements. In embodiments of the invention, both movable elements are actuated by a drive unit. In alternative embodiments, only the first movable element is drivable by a drive unit, while the other movable element can be effective as a check valve and is driven substantially only by an inflowing fluid. Alternatively to such a check valve using a movable element, as for example with reference to Fig. 10 has been described, the inlet could also be provided with a conventional non-return valve, for example a flapper valve which opens the inlet during the pumping movement of the first movable element and during the transport movement, with the fluid past the first movable element is transported, closes the inlet. Again alternatively, the inlet need not be provided with a valve, as long as the flow resistance of the first movable member through the inlet is greater than the flow resistance between the first movable member and the inner pumping element housing wall, as in such a case still a net pumping effect by the Sequence can be effected.

Housing parts of the pump element housing may advantageously consist of plastic and be produced, for example, using the injection molding technique. However, the housing parts may also be made using other suitable materials, for example by microstructuring techniques using semiconductor or ceramic materials or non-ferromagnetic metals. The one or more movable elements may advantageously be made of a ferromagnetic, soft magnetic or permanent magnetic material.

In embodiments of the present application, the first movable element may be permanent magnetic and designed as a magnetic dipole, wherein the magnetic axis of the dipole is oriented such that the movable element performs a rotational movement in addition to the translational nor upon application of an external magnetic field generated by a drive unit In this case, the first movable element is positioned in the pumping element housing in such a way that its fluidically effective geometry is changed in the sense of a valve, as described above with reference to FIG Fig. 5 was explained.

Described embodiments of the present invention include movable members that are in the form of a ball or a piston. However, it will be understood that the movable element (s) may have any shapes that provide the functionality described in conjunction with a corresponding pumping element housing.

As referring to Fig. 4 has been explained, can be attached to the movable element another sealing element which may consist of an elastic material and its fluidic effective geometry in response to the direction of movement of the movable member changes, wherein the movable member in conjunction with the sealing element has a valve function with the aid of which the ratio of the amount of fluid pumped out and the amount of fluid that has flowed back through the flow path between the movable element and the pump element housing during the pumping movement can be increased.

In embodiments of the present invention, the springs biasing the first movable member in position and / or the second movable member to the third position may be made of any suitable material, such as non-magnetic non-ferrous metal. In embodiments of the invention, the drive unit is formed in a separate housing such that it can be placed on different pump element housing, so that a plurality of pump types can be controlled with a drive unit.

In embodiments of the present invention, the rate of delivery of the pump during operation may be adjusted by changing the pumping frequency or by varying the pumping stroke of the first movable element. The pump frequency may be adjusted in embodiments of the invention by changing the frequency at which a current is impressed into the drive coil by the controller. In embodiments of the invention, the pumping stroke of the first movable member may be varied by changing the impressed current and thereby changing the generated magnetic force. Further, according to embodiments of the present invention, the delivery rate may be varied by varying the gaps between the first movable member and the pumping element housing and varying the spring preload F _be set before, for example, in advance in the design of the pump.

In embodiments of the present invention, a defined amount of fluid is pumped per pump stroke. In order to achieve a desired metering amount, a correspondingly necessary number of pumping strokes can thus be counted and carried out. As above with reference to the Fig. 7 to 9 has been described, via a ferromagnetic yoke and ferromagnetic pole pieces attached thereto, the magnetic flux can be selectively directed into the one or more movable elements. Moreover, by varying the cross-section of the pump housing in the ranges of movement of the movable elements, the magnetic flux through the balls can be adjusted in a targeted manner.

In embodiments of the present invention, a magnetic drive can be made up of two substantially identical units, each unit having its own control device and thus being able to control one of the movable elements individually. In alternative embodiments, the magnetic drive may consist of one unit, wherein a magnetic flux is simultaneously introduced into both movable elements via a ferromagnetic yoke and pole shoes. In yet alternative embodiments, the magnetic drive may consist of a unit, wherein a ferromagnetic yoke is made in two parts with pole shoes attached thereto, the drive coils being mounted in the region between the two movable elements on the yoke.

Finally, as discussed above with reference to FIGS Fig. 6a and 6b has been described, in embodiments of the present invention, the second housing having the drive unit, a further coil and a detection device, in which on the drive coil, an alternating magnetic field is superimposed, which in the further coil, a voltage is induced, which is measured and evaluated by the detection device, wherein the induced voltage in the further coil depends on the position of the movable elements in the pump element housing and wherein the detection device, the position of the movable elements and thus the position and function can determine the pump.

Although in the described embodiments the first movable element closes the drain when in the first position, in alternative embodiments the drain may not be completely closed when the first movable element is in the first position, still achieving a net pumping action can be.

In addition to the described magnetic drives, in alternative embodiments other drives may be used for the movable element (s), e.g. electrostatic drives or pneumatic drives.

Claims (15)

1. Pump element (10; 150) comprising:

   a pump element housing (14; 14a; 14c; 80; 152) defining a pump chamber (18; 82; 154);

   an inlet (20; 84; 156) into the pump chamber;

   an outlet (22; 86; 158) from the pump chamber;

   a first movable element (24; 24a; 24b; 24c; 88; 160) movable in the pump chamber between a first and a second position,

   wherein during a movement of the first movable element in the direction from the first to the second position, a flow resistance of a flow path from the first movable element through the inlet is higher than a flow resistance of a flow path (46; 46a; 46b; 46c) between the pump element housing and the first movable element, and

   wherein during a movement of the first movable element in the direction from the second position to the first position, a flow resistance of a flow path from the first movable element through the outlet is smaller than a flow resistance of the flow path between the pump element housing and the first movable element,

   so that a net flow through the outlet takes place during a reciprocating movement of the first movable element between the first and the second position, characterized in that the first movable element (24; 24a; 24b; 24c; 88; 160) closes the outlet when the same is in the first position.
2. Pump element according to claim 1 having a second movable element (26; 80; 162), by which the flow resistance of the flow path from the first movable element (24; 24a; 24b; 24c; 88; 160) through the inlet (20; 84; 156) can be varied.
3. Pump element according to claim 2, wherein the pump chamber housing (14; 80) contributes to a determination of a path for a movement of the second movable element (26; 80) from a third position to a fourth position, wherein, when the second movable element is in the third position, the flow resistance of the flow path of the first movable element through the inlet is smaller than when the second movable element is in the fourth position.
4. Pump element according to one of claims 1 to 3, wherein the flow resistance of the flow path (46b; 46c) between the pump element housing (14b; 14c) and the first movable element (24b; 24c) during the movement of the first movable element in the direction from the first to the second position is smaller than during the movement of the first movable element from the second to the first position.
5. Pump element according to claim 4, wherein the first movable element (24c) has a first position and a second position, wherein the flow resistance of the flow path between the pump element housing (14c) and the first movable element (24c) in the first position is smaller than in the second position.
6. Pump element according to claim 4, wherein the first movable element (24b) has a flexible sealing element (50), which provides a first flexibility during the movement from the first position to the second position, and a second flexibility during the movement from the second position to the first position, which is lower than the first flexibility.
7. Pump element (10; 150) according to claim 1, further comprising:

   a second movable element (26; 80; 162) movable in the pump chamber between a third and a fourth position;

   a first spring (28; 92; 164) biasing the first movable element to the first position;

   a second spring (30; 94; 166) biasing the second movable element to the third position;

   wherein a net flow through the outlet takes place during a reciprocating movement of the first movable element between the first and the second position and the second movable element between the third and the fourth position.
8. Pump element according to claim 7, wherein the first and the second spring (164, 166) are disposed between the first and the second movable element (160, 162), and wherein a spring stop (168) is disposed between the first and the second spring,
   wherein the inlet (156) is closed when the second movable element (162) is in the third position, and wherein the inlet (156) is open when the second movable element (162) is in the fourth position.
9. Pump having a pump element (10; 150) according to one of claims 1 to 8 and a driving unit (12; 12a; 102a, 102b; 120; 140), which is implemented to drive the first movable element from the first into the second position.
10. Pump according to claim 9, wherein the driving unit (12; 12a; 102a; 102b; 120; 140) and the pump element (10; 150) are separately structured and can be coupled to each other in a reversible manner, wherein the driving unit (12; 12a; 102a, 102b; 120; 140) and the pump element (10; 150) are implemented such that, during pumping, the driving unit does not come in contact with fluid to be pumped.
11. Pump according to one of claims 9 or 10, wherein the driving unit (12; 12a; 102a, 102b; 120; 140) comprises a device for generating a magnetic field by which the first movable element (24; 24a; 24b; 24c; 88; 160) is driven into the second position and wherein the first movable element has a ferromagnetic, soft-magnetic or permanent-magnetic material.
12. Pump according to claim 11 having a pump element according to claim 7, wherein the device for generating a magnetic field comprises a first device (106a) for generating a magnetic field, by which the first movable element (88) is driven into the second position, and a second device (106b) for generating a magnetic field, by which the second movable element (90) is driven into the fourth position, wherein the first and the second device for generating a magnetic field can be controlled separately.
13. Pump according to one of claims 9 to 12, further comprising a device (70, 72; 108; 108a, 108b) for detecting the position of the first movable element.
14. Method for adjusting the discharge rate of a pump according to one of claims 9 to 13, comprising at least one of the following steps:

    adjusting a frequency at which the first movable element is reciprocated;

    adjusting the stroke of the movement of the first movable element between the first and the second position;

    adjusting the flow resistance of the flow path between the first movable element and the pump element housing; and

    changing a spring bias biasing the first movable element to the first position.
15. Method for operating a pump according to one of claims 9 to 13, wherein during a reciprocating movement of the movable element a known amount of fluid is discharged from the outlet, wherein a number of reciprocating movements of the first movable element is counted for outputting a defined amount of dosage through the outlet.

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