EP3688865A1

EP3688865A1 - Electrical pump drive for a positive displacement pump, positive displacement pump and method therefor

Info

Publication number: EP3688865A1
Application number: EP18740813.3A
Authority: EP
Inventors: Conrad Nickel; Franz Pawellek
Original assignee: Nidec GPM GmbH
Current assignee: Nidec GPM GmbH
Priority date: 2017-09-28
Filing date: 2018-07-12
Publication date: 2020-08-05
Also published as: WO2019063158A1; DE102017122613B3; US20200251972A1; CN111164868A; BR112020006042A2

Abstract

The invention relates to an electrical pump drive for positive displacement pumps having pistons moved in an oscillating manner. The electrical pump drive is characterised in that the electrical pump drive comprises a rotary magnet (3) which has at least one electromagnet (30; 30a, 30b) and an armature (32) which can swivel about an axis and which is pivotable alternately between two working points by means of excitation of the at least one electromagnet (30; 30a, 30b); wherein the armature (32) is configured for coupling to a piston (2) which is moved in an oscillating manner.

Description

description

Electric pump drive for a positive displacement pump, positive displacement pump and

Method for this

The invention relates to an electric pump drive for positive displacement pumps with oscillating piston moving, a positive displacement pump with the same and a corresponding method for oscillating movement of a piston of a positive displacement pump.

In the prior art positive displacement pumps, compressors and vacuum pumps are known, which in contrast to a type of circulating positive displacement pumps such. Vane pumps, perform a discontinuous, in particular reciprocal movement of pump components. Displacement pumps of this kind drive displacement pistons, which oscillate between two points of inflection and thereby execute work cycles in which a charge exchange of an inflowing and outflowing delivery medium in a pumping chamber is effected. Including so-called double-stroke pumps are known which in both

Movement directions of a piston two opposite charge change, so generate an influx on one side of the piston and an outflow on the other side of the piston in the pump chamber at the same time. Furthermore, such positive displacement pumps differ by different, in particular linear and arcuate amplitudes of the oscillating piston movement.

According to the prior art in the prior art oscillating moving parts in displacement pumps exclusively by rotating electrical machines in the known designs of electric motors or other mechanical drive sources with a rotating drive shaft, which are coupled for example by means of belt drive or gear ratio driven. Further, between a pump assembly and a drive shaft is always a mechanical Actuator coupled, which produces by means of a connecting rod, a crank pin and a slot, a cam mechanism with cam, a control cam or the like to the drive shaft eccentric articulation of the moving parts.

In general, the kinematics of such a mechanism consists in converting the rotational drive movement into a reciprocal movement directed in the linear direction or in the working path of the piston. This results in an unbalanced dynamic, which manifests itself in the fact that to transfer a rotational continuous force into mutually accelerating forces dead centers must be overcome.

In practice, the dynamic imbalance brings various disadvantages. So when starting positive displacement pumps, a high drive torque to overcome the first dead center is required. This is especially true in the case of a cold start of a system in which a fluid having a temperature sensitive viscosity, e.g. a lubricating oil is conveyed. To ensure the operability that means the economic disadvantage that in proportion only nominal power relatively large-sized drive must be provided. Furthermore, in principle, an eccentric actuating mechanism must be provided, which is to be interpreted according to the application of the pump to demand on Verschleißfcstigkeit, space and costs. Based on this approach, there is room for improvement in various respects.

The present invention has for its object to provide an alternative pump drive for positive displacement pumps with oscillating moving piston.

The object is achieved by the features of the electric pump drive according to claim 1, the positive displacement pump according to claim 15 and the method according to claim 17.

The electric pump drive according to the invention is characterized in particular by the fact that it comprises a rotary magnet having at least one electromagnet and a pivotable about an axis armature, by means of the excitation of at least one electromagnet is mutually pivotable between two operating points, wherein the armature is adapted for coupling with an oscillatingly moving piston. Accordingly, the positive displacement pump according to the invention with a piston oscillating between two turning points is characterized in particular in that an electric pump drive comprises a rotary magnet which has at least one electromagnet and an armature pivotable about an axis which mutually alternately by energizing the at least one electromagnet between two operating points is pivotable, wherein the armature is coupled to the piston such that the inflection points of the oscillating movement of the piston are taken at the operating points of the armature.

Likewise, accordingly, the method according to the invention for oscillating a piston of a positive displacement pump between two inflection points by means of a rotary magnet is characterized by the steps of: generating a magnetic field by an electromagnet which applies a torque to the armature in a pivoting direction until the piston reaches a point of inflection, and expelling the magnetic field from the solenoid and / or generating a magnetic field of opposite polarity through an electromagnet that applies torque to the armature in the opposite pivoting direction until the piston reaches the other inflection point.

The invention thus provides for the first time to use a rotary magnet as a drive source of a pump drive for a non-umlaulende positive displacement pump.

The present invention in its most general form is based on the finding that a pump drive optimized for the reciprocal acceleration of a displacer ideally generates an alternately alternating moment with amplitude intensity in an electrodynamic manner. According to the invention, such a demand-responsive torque is suitably provided both in its dynamic intensity and in its kinematic alignment by a rotary magnet. This represents a fundamental departure from the drive concept of a continuous torque of a circumferentially directed driving force and a kinematic conversion of the drive movement.

By definition, according to the present disclosure, rotary magnets differ from rotating electrical machines in particular in that the executable movement of the armature of a rotary magnet is limited to a rotation angle between two operating points, that is, can not perform a complete revolution. In contrast to the stator of an electric motor with a plurality of excitation coils for generating a umlau fenden magnetic field, the rotary magnet is equipped depending on the embodiment, only with one or two electromagnets. In special forms for particularly high-torque designs, the rotary magnet can have a symmetrical arrangement of 4 or 6 electromagnets, as a result of which the executable rotation angle is geometrically reduced to a fraction of the factor.

Rotary solenoids, which are also referred to as rotary solenoids are actuators, which are known for example from plant engineering to convert a switch in a conveyor line or a so-called shutter as a baffle in a sorting path between two positions of a fork or fork.

In general, a distinction is made between proportional rotary magnet or rotary magnet with a return spring and bistable rotary magnet with an alternately reversed electromagnet or two alternately excited electromagnet. Analogous to the construction of an electric motor, the power transmission can be made by a polarity between the permanent magnet of the armature and fixed electromagnet, or the reluctance principle between armature poles and pole pieces of a magnetic circuit of a fixed electromagnet, such as by a pole ring. Known rotary magnets also differ in their construction, for example by a radial or axial arrangement between armature and electromagnet, whereby a torque of a rotational R el ati vbewegung is generated, or an axial arrangement with wedge-shaped grooves or surfaces and rolling elements between armature and Electromagnet, whereby an axially generated moment is converted into a helical relative movement. Such various and other known types and designs of rotary magnets or rotary solenoids are understood in the sense of the present disclosure under the combined name of a rotary magnet and are suitable for carrying out the invention and optionally provided.

To improve an electric pump drive for positive displacement pumps with respect to the disadvantages mentioned in the prior art as well as in further aspects, the invention provides various advantages explained below.

With a rotary magnet can be increased by short-term over-excitation of the electromagnet, the magnetic force, so that very high torques or torques are achieved. With suitable control, in particular at the beginning of a pivoting movement of the armature from one operating point to another, a high torque is applied, which decreases as the approach to the other operating point progresses, whereby covering the torque requirement of an oscillating acceleration can be covered. In addition, a rotary magnet offers fast reaction times and remains in the end position of an operating point without current supply. This reduces energy consumption and heat loss.

With the same dimensions, a rotary magnet achieves a larger exciter coil winding compared to the electric motor, and consequently a higher power input or electrodynamic force within the range of action of the coil, i. the working distance of the anchor, which meets the cold start requirement of various applications. At the same time, the number of coils, wirings, poles and other structural elements is lower, so that a compact, highly integrated design with few items and lower production costs is implemented.

Compared to brushless DC motors, which require a relatively complex ECU and power electronics, the technical requirements of the Control of the rotary magnet Simplifications and cost savings on the wiring of the power supply to.

In addition, the space and the cost of a mechanism as well as a risk of wear of the same depending on the type of pump assembly completely or be reduced.

Advantageous developments of the present invention are the subject of the dependent claims.

According to one aspect of the invention, an electromagnet of the rotary magnet can be excitable for mutual pivotal movement of the armature by an alternating current polarity. The change of direction of the armature is implemented purely control technology.

Thus, a simple construction of the rotary magnet is achieved with few electrical components, whereby the provision of a cost-effective electric pump drive a positive displacement pump is made possible.

According to one aspect of the invention, the rotary magnet may further comprise a return spring for the armature, and the electromagnet for the pivotal movement of the armature against a restoring force of the return spring excitable. In this case, a change in direction of the rotary magnet is implemented only by turning on and off the power supply.

Thus, a simple structure of the control circuit is achieved, whereby the provision of a cost-effective control of the electric pump drive, a positive displacement pump is made possible.

According to one aspect of the invention, the rotary magnet may comprise at least two electromagnets, wherein for mutually pivotal movement of the armature, the at least two electromagnets are alternately excitable. Thus, a power loss by reversing the polarity of a single electromagnet and a corresponding heat generation are prevented. Furthermore, the heat development is further reduced by dividing the current or power supply to two electromagnets as separate components.

According to one aspect of the invention, the armature of the rotary magnet may comprise at least one permanent magnet. This is followed by a pivoting movement of the armature from one operating point to the other operating point, a repulsive and / or attractive force of the magnetic polarity between the permanent magnet and the electromagnet.

Thus, a structurally simple structure of the rotary magnet is created, which achieves a high torque at anchor by magnetic forces between the magnetic poles. This allows the provision of an electric pump drive for positive displacement pumps having a good high power to compact size ratio.

According to one aspect of the invention, the armature of the rotary magnet can comprise a ferromagnetic armature body with pronounced armature poles, and the armature poles can be associated with pole shoes fixedly arranged in an operating point of the armature. In this case follows a pivotal movement of the armature from one operating point to the other operating point of the reluctance force to take the lowest air gap in the magnetic circuit of an electromagnet.

Thus, a structure of the rotary magnet without permanent magnets is achieved, which shows comparable to a reluctance motor an advantageous power consumption curve in the partial load range. This provides a low cost electric pump drive for positive displacement pumps without the use of rare earths for permanent magnetic alloys. Furthermore, the orientation of a magnetic circuit on the basis of the pole shoes at the same time allows a definition of the angle of rotation of the rotary magnet. According to one aspect of the invention, the armature of the rotary magnet can comprise an armature body with ferromagnetic armature poles, which have a higher magnetic permeability than other sections of the armature body, and the armature poles are assigned at a working point of the armature fixedly arranged pole pieces. In this case follows a pivotal movement of the armature from one operating point to the other operating point of the reluctance force for taking the lowest magnetic resistance through the anchor body in the magnetic circuit of an electromagnet.

Thus, an alternative construction of the rotary magnet with the aforementioned advantages of the reluctance principle is provided as a cost-effective electric pump drive for positive displacement pumps without the use of rare earths.

According to one aspect of the invention, the rotary magnet may comprise limiting means limiting a pivotal movement of the armature at the two operating points.

Thus, at each rotary magnet, in particular those with permanent magnets, the operating points of the rotary magnet can be set even more precisely. Further, if desired application specific, a short-term holding torque against such a mechanical stop can be generated. In contrast, if desired application-specific, as well as a rebound of the armature can be generated on the mechanical stop, which occurs if necessary before a piston of a piston against a chamber wall in the P ump order subassembly.

According to one aspect of the invention, the electromagnet and armature may be arranged such that an air gap between the armature poles and the pole shoes extends radially to the axis of the armature.

Thus, a design of the solenoid is provided that allows a short axial dimension of the electric pump drive to the pump assembly. According to one aspect of the invention, the electromagnet and armature may be arranged such that an air gap between the armature poles and the pole shoes extends axially to the axis of the armature.

Thus, a design of the solenoid is provided which allows for a slim radial dimension of the electric pump drive on the pump assembly.

According to one aspect of the invention, a yoke of an electromagnet, on which the pole pieces are formed, is formed as a pole ring, which is arranged concentrically around the armature or axially to the armature.

Thus, efficient introduction of the magnetic flux density of a magnetic circuit to the armature poles can be realized in a constructively favorable coaxial arrangement of the coil of the electromagnet, whereby an electric pump drive for positive displacement pumps with a small axial dimension is provided.

According to one aspect of the invention, the electric pump drive may further comprise detecting means for detecting a position of the armature.

Thus, feedback is optionally provided for controlling a control or power supply of the electric pump drive for positive displacement pumps, which can be realized by a displacement sensor or more cost-effectively by means of contacts at the operating points for detecting at least two armature positions.

According to one aspect of the invention, the electric pump drive may further comprise a control unit which controls an electric power supply to an electromagnet with respect to a timing and / or with respect to a current polarity of the supplied power. Such control functions can be realized by means of a pulse width modulator and by means of a bipolar amplifier in the form of standardized electronic components, whereby the provision of cost-effective control of an electric pump drive for positive displacement pumps is possible. This is particularly true in comparison to the required power electronics for a brushless DC motor, which is conventionally used as a pump drive.

According to one aspect of the invention, the electric pump drive with rotary magnet can drive a positive displacement pump with a pump assembly, which is designed as a rotary piston pump whose piston has two diametrically extending displacement sections, each of which is confined in a sector-shaped working chamber.

In combination with a pump assembly called a swing piston pump, the kinematics of the oscillating piston movement correspond to those of the armature, i. the trajectories are exactly congruent to each other interpretable. This allows a pump structure in which a mechanism between the electric pump drive and the pump assembly is eliminated and a compact integration is achieved by the pivot axis of the armature and the pivot axis of the piston are formed by a shaft.

According to one aspect of the invention, a control method of the electric pump drive for a positive displacement pump in the form of the aforementioned rotary piston pump, performing a switching on and off and / or reversing a current polarity of an electric power supply to the at least one electromagnet in dependence on a predefinable number of cycles of piston movements per Time unit.

With appropriate design, the amplitude of the pivotal movement of the armature corresponds to the amplitude of the pivotal movement of the piston. Since it is a Positive displacement is, there is also a fixed ratio between a piston stroke and funded volume flow rate. Thus, a conclusion to a fixed volume flow can be made in a simple manner by a clock speed of the piston movement, or this ratio can be applied to the control specification of an exact volumetri see delivery capacity. As a result, a simpler control can be realized, for example, or a flow meter can be dispensed with compared to circulating displacement pumps.

According to one aspect of the invention, the control method may further comprise performing an increase in a voltage of the electric power supply to the at least one electromagnet until it is detected by a detection means that the pivotal movement of the armature reaches the operating points.

Thus, a simple control can be realized, which determines the required minimum electrical power under the premise of a given volumetric flow rate and feeds.

The invention will be described in detail below with reference to a S chwenkkolbenpumpe as exemplary positive displacement pump, which is equipped with an Ausführungsfonn the electric pump drive, with reference to the drawings. In addition, with reference to representations of different construction forms of a rotary magnet of further possibilities for carrying out the electric pump drive, which are encompassed by the invention, with reference to the drawings. In these show:

1 shows a cross section through the exemplary rotary piston pump to explain the application of the electric pump drive according to the invention.

2 shows a longitudinal section through an exemplary rotary piston pump with an embodiment of the inventive electric pump drive, as Twin arrangement of a rotary magnet, which comprises two axially adjacent electromagnets and two anchor body is executed;

Figure 3 is a perspective view of an anchor body of the embodiment of the electric pump drive according to the invention from a side associated with the piston.

4 shows a perspective view of the other anchor body of the embodiment of the electric pump drive according to the invention from the opposite side to FIG. 3;

Fig. 5 is a detailed exploded view for explaining an alternative way of carrying out the electric pump drive according to the invention; and

Fig. 6 is a schematic exploded view for explaining a further alternative possibility for carrying out the electric pump drive according to the invention.

Referring first to Fig. 1, there will be described the construction of an exemplary rotary piston pump for use as an oil pump in a low-pressure lubricant system equipped with an embodiment of the electric pump drive according to the present invention. This rotary piston pump is further subject matter and more fully described in a co-pending patent application of the same Applicant of the present application.

In Fig. 1 of a pivot axis 12 from top left and bottom right two diametrically opposite overlapping e, sector-shaped working chambers 10 are shown extending in the pump housing 1 in a plane for pivotal movement of the rotary piston 2. The flanks of the working chambers 10 form contact surfaces for the oscillating piston 2. Shown from the pivot axis 12 from the top right and bottom left, two areas of a pump outlet 14 are arranged between the working chambers 10, which are connected via an arcuate channel in the pump housing 1. Between the working chambers 10 and the pump outlet 14, spangenförmige outlet valves 4 of the rotary piston pump are formed in the contact surfaces of the working chambers.

The pivoting piston 2 is fixed on the pivot axis 12, which is at the same time a drive shaft of the electric drive with a rotary magnet 3. The rotary piston 2 comprises two displacement sections 20, which are mutually pivoted in the working chambers 10 over a rotation angle of approximately 90 °, as shown by the double arrow. Inside, the rotary piston 2 is excluded as a hollow body and opened to the viewer's side of the representation, resulting in a cavity 25 results. The cavity 25 surrounds a receptacle of the pivot axis 12 and extends into the displacement sections 20.

In the flanks of the displacement sections 20, which are pivoted to the contact surfaces of the working chambers 10, intake valves 5 of the swivel piston pump are arranged. The inlet valves 5 allow a flow rate, which is sucked in via a central pump inlet 15, to pass through the cavity 25 into a working chamber 10 and block in the opposite direction from a pump chamber 10 to the cavity 25.

When the oscillating piston 2 moves counterclockwise from the starting position shown in FIG. 1, a volume of the conveying medium is displaced in front of the oscillating piston 2 or pushed out of the working chambers 10. In this case, the outlet valves 4 are opened on the pressure side of the rotary piston 2 in the pump housing 1 to the pump outlet 14, while the inlet valves 5 on the front pressure side of the rotary piston 2 block a passage to the cavity 25.

At the same time arises in the portion of the working chamber 10 on the rear side of the rotary piston 2, a negative pressure, so that a volume of the pumped medium, the over the pump inlet 15 is sucked, flows into the working chamber 10. In this case, the inlet valves 5 are opened on the rear suction side of the rotary piston 2 by the intake flow and are flowed through by the fluid in the cavity 25 to the working chamber 10, while the exhaust valves 4 lock the pump chamber 10 to the pump outlet 14. In a reverse pivotal movement back to the starting position of the rotary piston 2 in Fig. 1, the same operation. The rotary piston pump is thus a type of double stroke pump.

As shown in Fig. 3, the pump housing 1 further comprises a directed towards the working chambers 10 flange portion in which an embodiment of the electric drive with a rotary magnet 3 is accommodated. On a side of the pump housing 1 shown on the right, a further flange section closed by a cover is formed, in which a control circuit 39 of the electric drive 3 is accommodated. Supply connections, which lead to electromagnets 30 of the rotary magnet 3, pass out of the pump housing 1 through a connection pointing upward.

The electric drive shown is designed as a twin arrangement of a rotary magnet 3, which comprises two axially adjacent electromagnets 30a, 30b and two anchor bodies 32a, 32b, and thus forms a so-called type of bistable rotary magnet 3.

The annular electromagnets 30a, 30b are axially separated from each other and are in contact with two likewise axially separate pole rings 31a, 31b which form a respective one-sided pole system with a conclusion via a common ferrite core 33 or yoke. In the ferrite core 33, the pivot axis 12 is received, on which the armature 32 is pivotally mounted. The armature 32 has two anchor bodies 32a, 32b, each having a diametrically longer, and offset by 90 ° to have a diametrically shorter extension in the radial direction.

As can be seen in FIGS. 4 and 5, the anchor bodies 32a, 32b have the contour of a circular area, in which two opposite, recessed inside Circular arc segments are excluded. The sections between the recesses, which have the larger diametrical extent in the radial direction, form radially outwardly pronounced anchor poles 34. The anchor bodies 32a, 32b are jointly pivotally received in a respective central recess of a pole ring 31a, 31b. The recesses of the pole rings 31 a, 31 b have two opposite radially inwardly distinct pole pieces 35. The two anchor bodies 32a, 32b, ie in particular their anchor poles 34 are arranged offset by 90 ° to each other. Alternatively, however, also the pole shoes 35 of the two pole rings 31 a, 31 b may be formed offset by 90 ° to each other.

This results in the following operation of the illustrated embodiment of the pump drive according to the invention. When an electromagnet 30a is energized, the armature 32 pivots by the reluctance force to a position in which the corresponding anchor body 32a aligns with the armature poles 34 to the pole pieces 35 of the recess in the corresponding pole ring 31a, around the air gap and thus to reduce the magnetic resistance in a magnetic circuit, which is generated by the electromagnet 30 a in the pole ring 31 a, the anchor body 32 a and in conclusion via the ferrite core 33.

If the two electromagnets 30 a, 30 b are alternately supplied by the control circuit 39 with current, due to the staggered arrangement of the armature poles 34 and the pole shoes 35, a reciprocal pivotal movement of the pivot axis 12 is generated by 90 °, whereby the oscillating piston 2 in the above-described operation the rotary piston pump is driven.

More generally, the principle of a rotary magnet 3 of this embodiment corresponds to the following procedural steps: energizing the first electromagnet 30a with the electric power supply so that the armature 32 is pivoted from the first operating point to the second operating point by a magnetic field of the first electromagnet 30a; and energizing the second electromagnet 30b with the electric power supply, so that the armature 32 by a magnetic field of the second Electromagnet 30 b is pivoted from the second operating point to the first operating point.

As shown in Fig. 5 as an exploded view, there is another way to implement another imple mentation of the electric pump drive according to the invention in a known from the prior art design of a rotary magnet 3, which includes only one electromagnet 30 and to a helical return spring 36 , This design shown as an alternative variant of the rotary magnet 3 of the electric pump drive further comprises stop elements 37 as mechanical limiting means and ball bearings 38 for independent storage of the pivot axis 12 within the electric pump drive, a switch for the power supply as part of the control circuit 39 and other small parts such as a spacer sleeve, a circlip and the like. The anchor poles 34 of the armature 32 are axially pronounced, and are corresponding, axially distinct pole shoes 35 associated with a ferrite core plate 33 as a yoke, which produces a conclusion of the magnetic circuit to the pole ring 31 via the pivot axis 12 and a spring cage, which generates from the electromagnet 30 becomes.

As can be seen from the illustration in FIG. 5, such an operation possibility is subject to the following operation of the electric pump drive. When the solenoid 30 is energized by the switch of the control circuit 39 with an electric power supply, the armature 32 pivots by the reluctance force from a first operating point to a second operating point at which the armature poles 34 come into coincidence with the pole pieces 35 and an air gap of the magnetic Reduce the circle. In this case, the armature 32 abuts the stop em ducks 37 and is stopped at the second operating point. During the pivoting movement at the same time the return spring 36 is biased, which is fixed between the armature 32 and pole ring 31. After completion of the energizing s of the electromagnet 30 which generates a holding torque against the stop, the armature 32 is pivoted by the return spring 36 from the second operating point to the first operating point until it is stopped at the stop elements 37. This drives such an embodiment the electric pump drive according to the invention to the rotary piston 2 in the above-described operation of the rotary piston pump.

More generally, the principle of a rotary magnet 3 of this embodiment corresponds to the following procedural steps: energizing the electromagnet with the electric power supply, so that the armature 32 is pivoted by a magnetic field of the electromagnet 30 from the first operating point to the second operating point; and subjecting the energizing of the electromagnet 30 to the electrical power supply such that the armature 32 is pivoted by the restoring force of the biased return spring 36 from the second operating point to the first operating point.

Another possibility for implementing a further embodiment of the electric pump drive according to the invention, based on a known from the prior art design of a rotary magnet 3, which is shown in Fig. 6. This rotary magnet 3 comprises, similar to the first-mentioned embodiment, a two-pole excitation coil or two electromagnets 30a, 30b, which are arranged in the form of kidney-shaped windings on both sides of the pivot axis 12 and each comprise a ferrite core 33a, 33b or yoke. Axially adjacent to the electromagnets 30a, 30b, a disc-shaped armature 32 is arranged on the pivot axis 32, which carries two semicircular permanent magnets 34m as anchor poles 34. The permanent magnets 34m are magnetized in their longitudinal extent and applied in opposite directions on the armature 32. The polarization limit is symmetrical over the poles of the electromagnets 30a, 30b. The transmission range between the poles N / S contributes essentially to the transmission of power.

The mode of operation is similar to that of a permanently excited electric motor and follows the electrodynamics between the electric power supply and the resulting magnetic polarities. When the electromagnets 30a, 30b are energized, the armature 32 experiences a deflecting torque, the direction of rotation being determined by the polarity of the electromagnets 30a, 30b. By alternating excitation and suspension of each electromagnet 30a, 30b or by an alternating one Excitation with alternating polarity, the armature 32 between two operating points, which are preferably defined by mechanical limitations, pivoted back and forth. As a result, such an embodiment of the electric pump drive according to the invention drives the swivel piston 2 in the previously described mode of operation of the swivel piston pump.

Furthermore, this is a variant conceivable in which only one electromagnet 30 is arranged, which exerts a corresponding magnetic field with alternating polarity on the armature 32 by the electric power clock with alternating current polarity.

More generally, the principle of a rotary magnet 3 of this embodiment corresponds to the following procedural steps: energizing the electromagnet 30 or the electromagnets 30a, 30b with the electric power supply, so that the armature 32 by a magnetic field of the electromagnet 30a, 30b from the first operating point to the second Working point is pivoted; and energizing the electromagnet 30 or the electromagnets 30a, 30b with the reverse polarity electric power supply so that the armature 32 is pivoted by the reversed magnetic field of the electromagnet 30 or the electromagnets 30a, 30b from the second operating point to the first operating point.

For all illustrated and mentioned embodiments of the rotary magnet 3, the angle of rotation decreases due to a higher number of poles and the generated torque increases.

In addition, it is understood that the pump drive according to the invention can be used with other pump assemblies of positive displacement pump types than the described rotary piston pump. By a mechanically modified drive connection, the pump drive according to the invention can also be used in positive displacement pumps, in which a linear reciprocal piston movement is carried out, for example, in a cylindrical pump chamber. Here are both pump assemblies with a bidirectional piston and with eg two separately hinged pistons and constructions with or without Doppelhup principle suitable for the pump drive according to the invention.

Claims

claims

Electric pump drive for positive displacement pumps with oscillating pistons; characterized in that the electric pump drive comprises a rotary magnet (3) comprising at least one electromagnet (30; 30a, 30b) and an armature (32) pivotable about an axis which is energized by energizing the at least one electromagnet (30; 30a, 30b ) is mutually pivotable between two operating points; wherein the armature (32) is adapted for coupling to an oscillating piston (2).

Electric pump drive according to claim 1, wherein an electromagnet (30; 30a, 30b) of the rotary magnet (3) is excitable for alternating pivotal movement of the armature (32) by an alternating current polarity.

Electric pump drive according to claim 1, wherein the rotary magnet (3) further comprises a return spring (36) for the armature (32), and the electromagnet (30) for pivotal movement of the armature (32) against a restoring force of the return spring (36) is excitable.

Electric pump drive according to claim 1, wherein the rotary magnet (3) comprises at least two electromagnets (30a, 30b), and wherein for mutual pivotal movement of the armature (32) the at least two electromagnets (30a, 30b) are alternately excitable.

5. Electric pump drive according to claim 2, wherein the armature (32) comprises at least one permanent magnet (34m).

6. Electric pump drive according to claim 3 or 4, wherein the armature (32) comprises a ferromagnetic anchor body (32 a, 32 b) with pronounced anchor poles (34), and the anchor poles (34) in an operating point of the armature fixedly arranged pole shoes (35). assigned.

7. An electric pump drive according to claim 3 or 4, wherein the armature (32) comprises an armature body (32a, 32b) with ferromagnets see armature poles (34) having a higher magnetic permeability than other portions of the anchor body (32a, 32b), and the anchor poles (34) are assigned at a working point of the armature (32) fixedly arranged pole pieces (35).

8. Electric pump drive according to claim 6 or 7, wherein the electromagnet (30, 30a, 30b) and the armature (32) are arranged such that an air gap between the armature poles (34) and the pole pieces (35) radially to the axis of the armature (32) runs.

9. Electric pump drive according to claim 6 or 7, wherein the electromagnet (30, 30 a, 30 b) and the armature (32) are arranged such that an air gap between the armature poles (34) and the pole pieces (35) a ial to the axis of the Anchor (23) runs. An electric pump drive according to claim 9, wherein a yoke of an electromagnet (30, 30a, 30b) on which the pole pieces (35) are formed is formed as a pole ring (31, 31a, 31b) concentrically disposed around the armature (32) is.

Electric pump drive according to one of claims 1 to 10, wherein the rotary magnet (3) has limiting means (37) which limit a pivoting movement of the armature (32) at the two operating points.

Electric pump drive according to one of claims 1 to 1 1, further comprising a detection device for detecting a position of the armature (32).

An electric pump drive according to any one of claims 1 to 12, further comprising a control unit (39) which controls an electric power supply to an electromagnet (30, 30a, 30b) with respect to a timing and / or with respect to a current polarity of the supplied power.

Use of the electric pump drive with a rotary magnet (3) according to one of the preceding claims for driving a positive-displacement pump with an oscillating piston (2) moving between two turning points.

Positive displacement pump for gaseous and liquid fluids, comprising: a pump assembly having a working chamber (10), an inlet (15), an outlet (14) and a piston (2) oscillating in the working chamber (10) between two points of inflection, characterized in that an electric pump drive comprises a rotary magnet (3) which has at least one electromagnet (30, 30a, 30b) and an armature (32) pivotable about an axis, by means of excitation of the at least one electromagnet (30, 30a, 30b) between two operating points is mutually pivotable; wherein the armature (32) is coupled to the piston such that the inflection points of the oscillating movement of the piston (2) are taken at the operating points of the armature.

Positive displacement pump according to claim 15, wherein the pump assembly is designed as a rotary piston pump whose piston (2) has two diametrically extending displacement sections (20) which are each bounded in a sector-shaped working chamber (10).

Method for oscillating movement of a piston (2) of a positive displacement pump between two points of inflection by means of a rotary magnet (3), wherein: the rotary magnet (3) has at least one electromagnet (30, 30a, 30b) and an armature (32) pivotable about an axis, by means of excitation of the at least one electromagnet (30, 30a, 30b) is mutually pivotable between two operating points; and the armature (32) is coupled to the piston (2) such that the inflection points of the oscillating movement of the piston (2) are taken up at the operating points of the armature; the method comprising: Generating a magnetic field by an electromagnet (30; 30a), the magnetic field exerting a torque on the armature (23) in a pivoting direction until the piston (2) reaches a point of inflection; and suspending the generation of the magnetic field by the electromagnet (30) and / or

Generating a magnetic field of opposite polarity by an electromagnet (30; 30b), wherein the magnetic field of opposite polarity, a torque on the armature (32) in the opposite pivoting direction until the piston (2) reaches the other inflection point.

18. Control method for a positive displacement pump for gaseous and liquid fluids according to claim 1 5 or 16, comprising the step: switching on and off and / or reversing a current polarity of an electrical

Power supply to the at least one electromagnet (30, 30a, 30b) as a function of a predefinable number of cycles of piston movements per unit time.

19. The control method of claim 18, wherein the electric pump drive of the positive displacement pump further comprises detecting means for detecting a position of the armature (32); he is going to step

Increasing a voltage of the electric power supply to the at least one electromagnet (30, 30a, 30b) until it is detected by the detection means that the pivoting movement of the armature (32) reaches the operating points.