Fluid movement device

Abstract

A device for moving a fluid includes a dosing head in which a dosing chamber is arranged, and a displacement element which can be moved between a first and second position. The displacement element borders the dosing chamber, and the volume of the dosing chamber in the first position differs from the volume in the second position. drive unit for moving the displacement element from the first position to the second position and a return mechanism for moving the displacement element back are provided. The return mechanism has two magnetic parts. The first part is placed on the dosing head, the second part is connected to the displacement element, and the two parts are designed such that a magnetic force causes a force to be applied to the displacement element in the direction of the first position.

Claims

1. A device for moving a fluid, having a metering head (2) in which a metering chamber (3) is disposed, and a displacement element which can be moved back and forth between a first and a second position, wherein the displacement element delimits the metering chamber (3), and the volume of the metering chamber (3) in the first position of the displacement element differs from the volume of the metering chamber (3) in the second position, wherein a drive unit is provided for moving the displacement element out of the first position into the second position and a return mechanism is provided for moving the displacement element out of the second position into the first position, characterized in that the return mechanism (9, 10) comprises two parts, wherein each part is either a magnet or an element produced from a ferromagnetic material, wherein the first part (9) is disposed on the metering head (2), the second part (10) is connected to the displacement element, and the two parts (9, 10) are configured in a manner such that a magnetic force acting between the two parts (9, 10) exerts a force on the displacement element in the direction of the first position, and a recess (11) is disposed in a wall of the metering chamber (3), in which the first part of the return mechanism (9) which is disposed on the metering head (2) is positioned, wherein the recess (11) has dimensions which correspond to the size of the first part, so that the first part sits flush in the recess, wherein the recess (11) is further configured in a manner such that the second part of the return mechanism (9) which is disposed on the displacement element is at least partially positioned in the recess, such that the recess serves as a guide for the second part of the return mechanism.

2. The device according to claim 1, characterized in that the two parts (9, 10) of the return mechanism are configured and arranged in a manner such that a repulsive magnetic force acts between them.

3. The device according to claim 1, characterized in that the two parts (9, 10) of the return mechanism are configured and arranged in a manner such that an attractive magnetic force is exerted between them.

4. The device according to claim 1, characterized in that the return mechanism comprises a third part (12) which is a magnet or an element formed from a ferromagnetic material, wherein the third part (12) is connected to the metering head (2) and the three parts (9, 10, 12) of the return mechanism are configured and arranged in a manner such that an attractive magnetic force acts between the third part (12) and the second part (10) of the return mechanism.

5. The device according to claim 1, characterized in that the drive unit is a hydraulic drive unit.

6. The device according to claim 1, characterized in that the displacement element is a membrane.

7. The device according to claim 1, characterized in that the magnet is a permanent magnet.

8. The device according to claim 1, characterized in that the volume of the metering chamber (3) is smaller in the second position than in the first position.

9. The device according to claim 8, characterized in that the metering head (2) comprises a head cover (15) in which the metering chamber (3) is disposed, a fluid outlet (19) via which fluid from the metering chamber (3) can leave the metering head (2), and a drive unit block (17).

10. The device according to claim 9, wherein the first part (9) of the return mechanism is disposed in the head cover (15).

Description

(1) Further advantages, features and application possibilities of the present invention will become apparent from the description of embodiments below and also of the associated figures.

(2) FIG. 1 shows a diagrammatic sectional view in accordance with an embodiment of the present invention with a short stroke membrane, in which the magnetic force of the return mechanism acts repulsively.

(3) FIG. 2 shows a diagrammatic sectional view in accordance with an embodiment of the present invention with a short stroke membrane, in which the magnetic force of the return mechanism acts attractively.

(4) FIG. 3 shows a diagrammatic sectional view in accordance with an embodiment of the present invention with a long stroke membrane, in which the return mechanism is configured in three parts.

(5) FIG. 1 is a diagrammatic sectional view of a metering head 2 with a short stroke membrane 4.

(6) The metering head 2 is configured in two parts and consists of a head cover 15 and a drive unit block 17. A hydraulic channel 13 is disposed in the drive unit block 17 and is connected to a hydraulic drive unit (not shown). Furthermore, in the metering head 2 is a metering chamber 3, in which the displacement element configured as a membrane 4 is positioned. The membrane 4 is clamped between the head cover 15 and the drive unit block 17. The cavity disposed between the head cover 15 and drive unit block 17 is divided into a metering chamber 3 and a hydraulic chamber 5 by the membrane 4. An alternating pressure can be applied to the hydraulic chamber 5 by means of the hydraulic drive unit.

(7) The metering chamber 3 is connected to a fluid outlet 19 via a pressure side one way valve 21 and to a fluid inlet 20 via a suction side one way valve 22.

(8) If an alternating pressure is applied to the hydraulic chamber 5 by means of the hydraulic drive unit, this results in a back and forth movement of the membrane 4, with the consequence that the volume of the metering chamber 3 alternately increases and reduces. If the pressure in the hydraulic chamber 5 is raised, then the membrane 4 moves to the left in FIG. 1 and the volume in the metering chamber 3 is reduced, with the consequence that the pressure in the metering chamber 3 rises. As soon as the pressure in the metering chamber 3 is greater than a fluid pressure in a pressure line connected to the fluid outlet 19, the pressure side one way valve 21 opens and metered fluid is forced out of the metering chamber 3 via the fluid outlet 19.

(9) When the pressure in the hydraulic chamber 5 is reduced, the pressure in the metering chamber 3 falls and the membrane 4 moves to the right in FIG. 1. The pressure side one way valve 21 then closes. As soon as the pressure in the metering chamber 3 is lower than the pressure in a suction line connected to the fluid inlet 20, the suction side one way valve 22 opens and metering fluid is sucked into the metering chamber 3 via the fluid inlet 20. This procedure is then repeated continuously.

(10) The embodiment comprises a return mechanism which comprises a first part 9 and a second part 10. In the embodiment shown, both the first part 9 and also the second part 10 are configured as permanent magnets which are disposed in a manner such that identical poles are opposite to each other, so that the second part 10 is repelled from the first part 9.

(11) The head cover 15 comprises a recess 11 in which the first part 9 is disposed. The second part 10 is connected to the membrane 4 and is also partially disposed in the recess 11. The recess 11 here also acts as a guide for the second part 10.

(12) In fact, the pressure provided by the hydraulic drive unit is somewhat increased in this embodiment, because now an additional force has to be applied to the membrane 4 which acts against the repulsive magnetic force between the first part 9 and the second part 10, however the return movement of the membrane 4, i.e. when the membrane 4 is supposed to move towards the right, is accelerated by the magnetic force between the first and the second part 9, 10.

(13) FIG. 2 shows a diagrammatic sectional view of a second embodiment of the device in accordance with the invention. As far as possible, the same reference numerals as those used in FIG. 1 have been used.

(14) In analogy with FIG. 1, FIG. 2 shows a metering head 2 which is configured in two parts and which consists of a head cover 15 and a drive unit block 17. The drive unit block 17 comprises an adjoining hydraulic channel 13 which is connected to a hydraulic drive unit (not shown). In addition, a metering chamber 3 is disposed in the metering head 2; the membrane 4 is located in the metering chamber and is clamped between the head cover 15 and the drive unit block 17. Adjacent to this membrane 4 and opposite to the cavity which is configured as the metering chamber 3 is a second cavity which corresponds to the hydraulic chamber 5. In addition to these elements, the head cover 2 additionally comprises a pressure side one way valve 21 which adjoins the metering chamber 3 and is in fluid communication therewith, which is connected to a fluid outlet 19 and a suction side one way valve 22 which is connected to a fluid inlet 20.

(15) In contrast to the embodiment in FIG. 1, in this case the first part 9 is not disposed in the metering chamber 15, but in a recess 11 in the drive unit block 17.

(16) In addition, the two parts which are configured as magnets in this case are disposed with different poles facing each other, so that the two parts 9, 10 attract. In this regard, the magnet for the second part 10 is integrated into the membrane 4.

(17) The function essentially corresponds to the function of the embodiment shown in FIG. 1. However, in this case, in addition, the attractive force between the first and second parts 9, 10 must be overcome by the hydraulic drive unit. If the pressure in the hydraulic chamber 5 is reduced, then the attractive force between the first and the second parts will ensure a reliable and rapid return of the membrane 4 into the first (right hand) position.

(18) FIG. 3 shows a diagrammatic sectional view of a metering head 2 configured in two parts which consists of a head cover 15 and a drive unit block 17. The metering head 2 has a metering chamber 3 disposed in it, which is connected to a fluid outlet 19 via a pressure side one way valve 21 and to a fluid inlet 20 via a suction side one way valve 22. Adjoining the metering chamber, but interrupted by a membrane which is clamped between the drive unit block 17 and the head cover 15, is a hydraulic chamber 5, wherein the hydraulic chamber is connected to a hydraulic drive unit (not shown) via a hydraulic channel 13.

(19) In this case, the membrane employed is a long stroke membrane 6 by means of which larger quantities of a fluid than in the case of a short stroke membrane can be conveyed, because the stroke, i.e. the distance between the first (right) position and the second (left) position of the membrane is greater. Because the magnetic force used in accordance with the invention is strongly dependent on the separation of the parts of the return mechanism, the embodiments shown in FIGS. 1 and 2 are of only limited use, because if the separation is too large, the desired additional magnetic force in accordance with the invention is only very weak.

(20) Therefore, in the embodiment shown in FIG. 3, a return mechanism which is in three parts is envisaged, wherein the three parts are disposed in a manner such that the first part 9 of the return mechanism is supported in a recess 11 in the head part 15, the second part 10 of the return mechanism is connected to a membrane 6 and the third part 12 is connected to the drive unit block 17. In this example, the three parts of the return mechanism consist of three permanent magnets, preferably of three structurally identical disk magnets.

(21) The magnets are configured and arranged in a manner such that between the first part 9 and the second part 10 of the return mechanism, a repulsive magnetic force prevails, and between the second part 10 and the third part 12, an attractive force prevails.

(22) Basically, the third embodiment is a combination of the first and the second embodiments.

(23) If the pressure in the hydraulic chamber 5 is increased by means of the hydraulic drive unit, then the membrane 6 is moved to the left against the attractive magnetic force between the second part 10 and the third part 12 and against the repulsive magnetic force between the first part 9 and the second part 10.

(24) If the hydraulic drive unit does not exert any more force, then the superimposition of the repulsive magnetic force and the attractive magnetic force of the magnets brings about a return of the membrane from the second position into the first position.

(25) With the aid of the superimposition of the magnetic forces, by using a third part of the return mechanism, a larger magnetic force is obtained, the consequence of this being that with this embodiment of the device in accordance with the invention, longer stroke lengths are possible, as are required in pumps in which long stroke membranes 6 are used.

LIST OF REFERENCE NUMERALS

(26) 2 metering head 3 metering chamber 4 short stroke membrane 5 hydraulic chamber 6 long stroke membrane 9 first part of return mechanism 10 second part of return mechanism 11 recess 12 third part of return mechanism 13 hydraulic channel 15 head cover 17 drive unit block 19 fluid outlet 20 fluid inlet 21 pressure side one way valve 22 suction side one way valve