Pumping system for gaseous and liquid media

Abstract

The invention relates to a pumping system (1), in particular, for transporting gaseous and/or liquid media having two parallel hydraulically operated oscillating piston pumps (2, 3) whose pistons (8) are moved by means of electromagnetic fields, whereby the electromagnetic fields are generated in field coils (10, L1, L2) by means of half-wave direct current pulse. The invention distinguishes itself by a circuit arrangement (19) that can be connected to an alternating current source having two parallel electric branches that are connected to the field coils (L1, L2) of one of the oscillating pumps (2, 3) respectively, wherein the circuit arrangement (19) is equipped in such a way that the field coils (10, L1, L2) are operated electrically out of phase so that the oscillating piston pumps (2, 3) are operated with a phase displacement of 180. The invention further relates to a method for operating the pumping system electrically, and a circuit configuration for the pumping system and accordingly, for executing the method.

Claims

1. A pumping system for transporting gaseous and/or liquid media, the pumping system comprising: a first hydraulically operated oscillating piston pump comprising a first field coil and a first piston that is movable via a first electromagnetic field of the first field coil resulting from a first half-wave direct current pulse; a second hydraulically operated oscillating piston pump comprising a second field coil and a second piston that is movable via a second electromagnetic field of the second field coil resulting from a second half-wave direct current pulse; a circuit arrangement that is configured to be connected to an alternating current source, the circuit arrangement having a first electric branch and a second electric branch, the first electric branch being connected with the first field coil and the second electric branch being connected with the second field coil; and a control unit, wherein the control unit and the circuit arrangement are configured to facilitate operation of the first hydraulically operated oscillating piston pump and the second hydraulically operated oscillating piston pump in a first mode in which the first hydraulically operated oscillating piston pump and the second hydraulically operated oscillating piston pump operate electrically out of phase and alternatively in a second mode in which the first hydraulically operated oscillating piston pump and the second hydraulically operated oscillating piston pump operate electrically in phase, wherein in a first switching state of the circuit arrangement corresponding to the first mode, a first connection of the alternating current source is connected via a first rectifier element with a first electric inlet of the first field coil and directly with a second electric outlet of the second field coil and a second connection of the alternating current source is connected via a second rectifier element with a second electric inlet of the second field coil and directly with a first electric outlet of the first field coil, and wherein in a second switching state of the circuit arrangement corresponding to the second mode, the second connection is connected via the first rectifier element with the first electric inlet of the first field coil and via the second rectifier element with the second electric inlet of the second field coil, wherein the first connection is connected directly with the first electric outlet of the first field coil and the second electric outlet of the second field coil.

2. The pumping system as recited in claim 1, wherein, in the first electric branch, the first rectifier element is provided in series with the first field coil, and, in the second electric branch the second rectifier element is provided in series with the second field coil.

3. The pumping system as recited in claim 1, further comprising: a first hydraulic branch comprising the first hydraulically operated oscillating piston pump and a first check value; and a second hydraulic branch comprising the second hydraulically operated oscillating piston pump and a second check valve.

4. The pumping system as recited in claim 3, wherein the first check valve has a valve-locking element and the second check valve has a valve-locking element, wherein each valve-locking element is formed spherical or plate shaped.

5. The pumping system as recited in claim 1, wherein the first piston of the first hydraulically operated oscillating piston pump and the second piston of the second hydraulically operated oscillating piston pump are pressure pistons that are respectively mounted on central return springs.

6. A method of operating the pumping system of claim 1, the method comprising: the control unit placing the circuit arrangement in the first switching state; and the control unit placing the circuit arrangement in the second switching state.

Description

(1) Shown are:

(2) FIG. 1 shows a pumping system according to a first embodiment of the invention.

(3) FIG. 2 shows a circuit arrangement according to a first embodiment of the invention.

(4) FIGS. 3a-d show the phase-displaced excitation of the field coils; and

(5) FIGS. 4a, b show a circuit arrangement according to a further embodiment of the invention.

(6) FIG. 1 shows a pumping system 1 having two hydraulic oscillating piston pumps 2, 3 that are operated connected in parallel between an inlet 4 and an outlet 5 in one pump branch 6, 7 respectively. The upper oscillating piston pump 2 and the upper pump branch 6 are shown in cross section, the lower oscillating piston pump 3 and the lower pump branch 7 are shown in a top view, however, their structure corresponds to that of oscillating piston pump 2 and pump branch 6.

(7) Pumps 2, 3 respectively comprise an axially displaceable piston 8 having an anchor element 9 and a field coil 10. Piston 8 is mounted in a first axial direction at a first return spring 11 (pressure spring) and in the opposite direction at a second return spring 12 (pressure spring).

(8) Piston 8 is provided with a central bore 13 and two transverse bores 14 in stepped manner. A first valve 15 comprises a sphere mounted on a spring 16. A second valve 17 comprises a plate-slider mounted on a spring 16. The valves serve as check valves.

(9) As a result of the back and forth motions of piston 8 and due to the interaction of valves 15, 17 the fluid from inlet 4 is pumped to outlet 5 in spurts. When current is applied to field coil 10, piston 8 displaces axially to the right via the anchor and compresses spring 11. When the supply of current to field coil 10 is interrupted, piston 8 is again displaced to the left due to the force of the compressed spring 11, as a result of which a medium (here a fluid) of the hydraulic system is pressed toward the left. This also applies to the oscillating piston pump 3.

(10) For the phased excitement of the field coils in oscillating piston pumps 2, 3 a circuit arrangement is provided that is shown in FIG. 2. The circuit arrangement is connected to a 50 Hz AC mains. The AC mains power supply comprises a first mains cable KI1 and a second mains cable KI2 that are poled differently. The AC mains power supply supplies alternating current with sinusoidal characteristics.

(11) L1 identifies field coil 10 (FIG. 1) of the first oscillating piston pump 2. L2 identifies the field coil of the second oscillating piston pump 3. Field coils L1 and L2 are connected to mains cables KI1 and KI2 (AC connections) switched in parallel. Thus, the circuit arrangement comprises two electrical branches that are switched in parallel, whereby each of the branches is connected to one of the field coils L1 and L2.

(12) At its inlet, the first field coil L1 has an integrated rectifier diode D1 so that the first electric branch formed by field coil L1 has a diode D1 connected in series with field coil L1. The first mains cable KI1 is connected with the inlet of field coil L1 of the first oscillating piston pump via the integrated half-wave rectifier D1. Simultaneously, the first mains cable KI1 is connected in parallel with the outlet of the second field coil L2. The outlet of the second field coil L2 does not have an integrated half-wave rectification; this means that the field coil is connected directly with the first mains cable KI1.

(13) At its inlet, the second field coil L2 has an integrated rectifier diode D2 so that the second electrical branch formed by field coil L2 has a diode D2 that is connected in series with field coil L2. The second mains cable KI2 is connected with the inlet of field coil L2 of the second oscillating piston pump via the integrated half-wave rectification D2. Simultaneously, the second mains cable KI2 is connected in parallel with the outlet of the first field coil L1. The outlet of the first field coil L1 does not have an integrated half-wave rectification which means that the field coil L1 is connected directly with the second mains cable KI2.

(14) Diodes D1 and D2 are switched antiparallel relative to mains cables KI1 and KI2, or poled opposite. This means that the return direction and the flow direction are oriented opposite. If the current is coming from KI1, D1 is in the flow direction and D2 in the reverse direction. In contrast, if the current comes from KI2, it is reversed.

(15) FIGS. 3a through 3d show the alternating excitement of the first and second field coils L1 and L2. FIG. 3a shows the first branch of field coil L1 that is connected with the mains having Diode D1 connected in series. FIG. 3b shows the voltage characteristic U of sinusoidal alternating currentcorrespondingly, the characteristic voltage curve trails phase-displacedat the outlet of diode D1. FIG. 3c shows the second branch of field coil L2 that is connected to the mains having diode D2 connected in series. FIG. 3d shows the voltage curve U of sinusoidal alternating current at the outlet of diode D2. Due to the antiparallel arrangement of diodes D1 and D2, diode D1 permits only the positive half-waves U1 of the supply voltageand thus the currentto flow through field coil L1. In contrast, diode D2 permits only the negative half-waves U2 of the voltage supply to flow through field coil L2. Consequently, the mains current or the mains voltage is divided phased between field coil L1 and L2. During the phases of the positive half-waves the piston in the first oscillating piston pump is displaced due to field coil L1, whereas the piston is reset by the spring in the phase of the negative half-waves. In the other oscillating piston pump it is precisely the reverse. While in the phases of the positive half-waves, the piston in the second oscillating piston pump is reset by the spring, whereas the piston in the phase of the negative half-waves is displaced by field coil L2.

(16) The circuit shown in FIG. 2 can also take place the other way around by interchanging KI1 and KI2. In this case, the field coil L1 is supplied with current only during the phases of the negative half-waves and the field coil L2 is supplied with current only during the phases of the positive half-waves.

(17) The circuit arrangement shown in FIGS. 4a and 4b shows an integrated control unit 20. By means of control unit 20, the operating condition of the pumping system can be switched from a phase-displaced operation to an in-phase operation in which the pumps run synchronously. Here, circuit arrangement 19 is likewise connected to a 50 Hz mains power supply by a first power cable KI1 and a second power cable KI2 that are poled differently. The AC power mains supplies alternating current with sinusoidal characteristics.

(18) Components L1, L2, D1 and D2 correspond to the components shown in FIG. 2.

(19) The first field coil L1 has an integrated rectifier diode D1 at its inlet and the second field coil L2 has rectifier diode D2 at its inlet.

(20) Control unit 20 can be switched between two states. In a first state that is shown in FIG. 4a, control unit 20 connects the first power cable KI1 with the inlet of field coil L1 of the first oscillating piston pump via integrated half-wave rectifier D1 (connection 1b-3b) and the outlet of field coil L1 directly with KI2 (connection 1a-3a). The outlet of field coil L2 is connected directly with KI1. Simultaneously, the second power cable KI2 is connected with the inlet of field coil L2 of the second oscillating piston pump via integrated half-wave rectification D2, and the second power cable KI2 is connected in parallel with the outlet of the first field coil L1.

(21) In the first switching state, the circuitry of the components corresponds to the configuration shown in FIG. 2. The second switching state is shown in FIG. 4b. By switching the control unit 20, the second power cable connection KI2 is separated from the outlet of the first field coil L1 and the outlet of the first field coil L1 is connected directly with the first power cable connection KI1 (connection 1a-2a). Further, the connection between the half-wave rectification D1 and the mains connection KI1 is separated and the half-wave rectification D1 is connected with mains connection KI2 (connection 1b-2b). The connection of the second field coil L2 to mains connections KI1 and KI2 remains unchanged. Due to the switching, first field coil L1 is connected to mains connections KI1 and KI2 just like the second field coil.

(22) In the first switching state (FIG. 4a) of control unit 20, the diodes D1 and D2 are switched antiparallel relative to power cables KI1 and KI2, and accordingly poled opposite. This means that the reverse direction and the flow direction are oriented opposite. If the current is flowing coming from KI1, D1 is in flow direction and D2 in reverse direction. In contrast, if the current is flowing coming from KI2, it is reversed. Thereby, the phase-displaced operation is generated.

(23) In the second switching state (FIG. 4b) of control unit 20, diodes D1 and D2relative to power cables KI1 and KI2are connected poled in the same directions. This means that the reverse direction and the flow direction are oriented in the same direction. If the current is flowing coming from KI1, D1 and D2 are in the reverse direction. If the current is flowing coming from KI2, it is the reverse.

(24) As the result, the in-phase operation is generated and the hydraulic pumps connected in parallel generate a pulsed stream of the gaseous or liquid medium.

REFERENCE NUMBERS

(25) 1 pumping system 2 oscillating piston pump 3 oscillating piston pump 4 inlet 5 outlet 6 pump branch 7 pump branch 8 piston 9 anchor 10 field coil 11 return spring 12 spring 13 central bore 14 transverse bore 15 valve 16 spring 17 valve 18 spring 19 circuit arrangement 20 control unit KI1 first AC power line KI2 second AC power line L1 first field coil L2 second field coil D1 first rectifier diode D2 second rectifier diode