US20120230847A1

US20120230847A1 - Vibrating armature pump

Info

Publication number: US20120230847A1
Application number: US13/261,210
Authority: US
Inventors: Rudolf Lonski
Original assignee: Vermietungsgesellschaft Harald Schrott and Sysko AG GbR
Current assignee: Vermietungsgemeinschaft Harald Schrott & Sysko AG GbR; Vermietungsgesellschaft Harald Schrott and Sysko AG GbR
Priority date: 2009-09-09
Filing date: 2010-09-08
Publication date: 2012-09-13
Also published as: CN102597517A; EP2475887A1; DE102010044775A1; WO2011029577A1

Abstract

The invention relates to a vibrating armature pump having a pump housing, which comprises a cylinder for receiving a substantially linearly displaceable pump piston unit (10). The pump piston unit (10) comprises at least one pump element (11) for pumping the pumping fluid and a drive element (12) for driving the pump element (11). Both elements are designed separately and arranged loosely one behind the other.

Description

The invention relates to a vibrating armature pump having a pump casing, which comprises a cylinder for receiving a pump piston unit adjustable essentially linearly, according to the preamble of claim 1.

PRIOR ART

Vibrating armature pumps are distinguished by a piston which vibrates back and forth in a movement axis and which is composed at least partially of magnetic or magnetizable material and is driven via an electromagnetic coil.
The piston of a vibrating armature pump, when it penetrates into a cylinder, displaces a fluid, in particular water, located therein. When the piston is extended out of the cylinder, the latter is filled with fluid or water again via a piston, so that cyclical pumping actions can take place during the oscillation of the pumping process.
For this type of functioning, it is necessary for the inner space of the cylinder to have a fluid-tight configuration. This sealing must be ensured in any position of the piston, and therefore a sealing surface formed is usually a sliding surface which also performs this sealing function during the axial movement of the piston.
Vibrating armature pumps of this type are described, for example in the publications EP 0 288 216 B1, DE 10 2005 048 765 A1 or DE 600 16 905 T2. These vibrating armature pumps disclose composite pistons with a part composed of a ferromagnetic metallic material and with a part composed of a non-metallic and non-ferromagnetic material, the parts being connected positively and nonpositively to one another for the purpose of operation. The connection of the two parts may be carried out, for example, by pinching, caulking, rolling, clamping, pressing, bonding, welding, shrinkage or by other methods of manufacture. In this case, for example where one part is concerned, undercuts are provided, into which corresponding protrusions of the other part are latched when the parts are plugged together.
The disadvantage of this, however, is that the execution of corresponding undercuts or connecting process steps is complicated and is therefore cost- intensive in economic terms.

OBJECT AND ADVANTAGES OF THE INVENTION

By contrast, the object of the invention is to propose a vibrating armature pump with a pump casing, which comprises a cylinder for receiving a pump piston unit adjustable essentially linearly, said vibrating armature pump being capable of being produced more favorably than the prior art in economic terms.
On the basis of a vibrating armature pump of the type initially mentioned, this object is achieved by means of the characterizing features of claim 1. Advantageous versions and developments of the invention are possible as a result of the measures mentioned in the subclaims.
Accordingly, a vibrating armature pump according to the invention is distinguished in that the pump piston unit has at least one separate pump element for pumping the pump fluid and one separate drive element for driving the pump element. This means that according to the invention, during operation, two separate or loose elements form the pump piston unit vibrating back and forth. Accordingly, the two separate or loose elements of the pump piston unit are arranged next to one another or one behind the other during operation, without there being a (materially integral or nonpositive or unreleasable) connection between the two elements, that is to say between the pump element and the drive element.
With the aid of the two elements or of the pump element and of the drive element, which are separate during operation, connecting process steps or complicated structural measures for connecting the two elements become superfluous, so that, according to the invention, these are dispensed with, thus saving corresponding costs. Accordingly, a vibrating armature pump according to the invention can be produced especially favorably in economic terms.
It was shown, surprisingly, that connection of the two elements or of the separate pump element and of the separate drive element is not absolutely necessary for the proper operation of the vibrating armature pump. Thus, for example, a pinching operation according to EP 0 288 216 B1 or a pressurizing operation according to DE 600 16 905 T2 may be dispensed with, which signifies corresponding savings in terms of production. Above all, economic benefits, as compared with this prior art, are also achieved in that corresponding clearances or undercuts or the like are dispensed with.
According to the invention, the pump element which is separate during operation and the drive element which is separate during operation are advantageously arranged loosely next to one another or so as to lie one behind the other, that is to say, in particular, even during the movement of the pump piston unit back and forth. For this purpose, for example, planar contact surfaces of the separate pump element and/or of the separate drive element are advantageous.
Advantageously, the pump element has a first stop for the drive element and the drive element has a second stop for the pump element. What is achieved thereby is that a defined contact or a defined contact surface, to be precise the corresponding stops, are present, with the result that a dimensionally accurate pump piston unit can be implemented. For example, the stops are designed as planar surfaces, so that comparatively high forces, above all from the drive element for driving the pump element, can be transmitted between the two elements which are separate or loose during operation. Furthermore, active forces, for example advantageous restoring forces or the like, can be transmitted from the pump element to the separate drive element.
Preferably, at least one first spring element is provided for acting with force upon the pump piston unit and/or the pump element. For example, the first spring element is designed in such a way that the drive movement is somewhat braked. The drive movement may preferably be generated by at least one electric drive, in particular by an electromagnetic coil. An advantageous or defined pump movement or drive movement for driving the separate or loose pump element can thereby be implemented.
Advantageously, the first spring element ensures that the two loose or separate parts are to a limited extent held together or connected, particularly in the state of rest and also during the pumping action or pumping movement.
In an advantageous variant of the invention, at least one second spring element is provided for acting with force upon the pump piston unit and/or the drive element and/or the first spring element, the spring force of the second spring element advantageously being directed opposite to the spring force of the first spring element. Advantageously, the second spring element is tensioned or compressed by means of the drive or drive unit.
Advantageously, the second spring element presses or pumps the fluid, that is to say the spring stroke of the second spring element corresponds essentially to the pumping stroke of the vibrating armature pump according to the invention. The second spring element can consequently be designed as a restoring spring for restoring the pump piston unit or the two elements separate during operation, that is to say the separate pump element and the separate drive element. In this case, the spring force of the second spring element advantageously acts as a restoring force for restoring the pump piston unit, pumping advantageously taking place at the same time during the restoring action.
Preferably, the drive element is composed essentially of a ferromagnetic material. It thereby becomes possible that at least one electromagnetic drive coil or the like advantageously transmits the pumping force or pumping energy to the pump element of the pump piston unit or said pump element is thereby acted upon. It was shown that a drive of the vibrating armature pump or its pump piston unit movable linearly back and forth by means of an electromagnetic coil can be produced and operated especially favorably in economic terms.
Preferably, the drive element is composed essentially of magnetic or magnetizable material, in particular of magnetic or magnetizable metal, preferably of magnetic or magnetizable high-grade steel. When high-grade steel is used as material for the drive element, it is especially advantageous that this material generally does not rust or is not oxidized even in liquid media, such as, for example, water. The vibrating armature pump according to the invention thereby advantageously acquires a long service life.
By contrast, a magnetic or magnetizable material, such as (rusting) steels, which, for example with a surface coating, are designed to be appropriately corrosion-resistant, could perfectly well also be used. It was shown, however, that corresponding coverings or coatings, etc. are worn away due to the back and forth movement or to the vibration of the pump piston unit, and this results in adverse wear and may expose the rusting material. Vibrating armature pumps according to the invention should be able to execute approximately million strokes or more without being adversely affected. This can advantageously be achieved, above all, with a high-grade steel as material- for the drive element.
In a particular development of the invention, the pump element is composed essentially of a plastic, above all thermal plastics and/or thermal setting plastics, in particular even mixtures of both, being considered. It was shown that corresponding plastics have especially good sliding properties and are also inexpensive. Precisely the sealing function of the pump element can be implemented especially effectively by means of an advantageous plastic. For example, the thermal plastic used may be polyacetate, PEEK, Vespel or the like, and/or the thermal setting plastic used may be BMC or the like. These plastics are resistant to chemicals and/or are cost-effective and/or have an advantageous sliding property.
Alternatively to this, a high-grade steel may also be used as material for the pump element. This material, when used for the pump element, is distinguished, above all, in that it is abrasion-proof and corrosion-resistant and is also resistant to dry running and/or temperature-resistant.

Exemplary Embodiment

An exemplary embodiment of the invention is illustrated in the drawing and is explained in more detail below by means of the figures in which, in particular,

FIG. 1 shows a diagrammatic longitudinal section through a vibrating armature pump according to the invention, and

FIG. 2 shows a diagrammatic longitudinal section through a vibrating armature piston unit according to the invention which is arranged between two spring elements.

The vibrating armature pump 1 according to FIG. 1 comprises a two-part pump casing 2 which is fastened to a yoke 3 of an electromagnetic coil 4.
The pump casing 2 comprises a tubular armature receptacle 6 which is plugged into the interior of the coil 4, and a cylinder part 7 which bears via a flange 8 against the yoke 3.
A pump piston unit or pump piston 10 is introduced into the pump casing 2 and comprises a pump element or piston part 11 and a drive element or magnetic part 12.
The piston part 11 is of tubular design with an axial passage and penetrates into a cylinder 13 which is formed in the cylinder part 7.
The pump piston 10 and therefore also the piston part execute during operation cyclical axial displacements in the direction of the double arrow A, that is to say it vibrates periodically back and forth in the axial direction.
On the side lying opposite the magnetic part 12, the cylinder 13 is closed by means of a transverse web 16 which has a central through orifice 17. A compression spring 18 is supported on the transverse web 16 toward the piston side and presses a sealing body 19 onto the outlet of the tubular piston part 11.
On that side of the transverse web 16 which lies opposite the piston 11, the cylinder part 7 is prolonged in tubular form and at its outer end forms the delivery-side connection piece 20 of the vibrating armature pump 1. A supporting ring 21 is introduced into the connection piece 20 and forms a stop for a further compression spring 22 which presses a sealing body 23 against the transverse web 16 and at the same time closes the through orifice 17.
The pump piston 10 is provided, starting from the piston part 11, in the direction of the magnetic part with a two-stage cross-sectional widening. The piston part 11 having a small cross section is thus followed by an intermediate part 24 with a medium cross section and by the magnetic part 12 with a large cross section. In the intermediate part 24, a transverse bore 25 is formed which is connected to the axial passages 26, 27 of the piston part 11, on the one hand, and of the magnetic part 12, on the other hand.
A first compression spring 28 surrounds the intermediate part 24 and is supported on one side on the step of the piston part 11 having the large cross section. In this case, a web 14 is provided, which advantageously ensures radial centering of the piston part 11 with respect to the magnetic part 12. Moreover, the two parts 11, 12 have a contact 5 or in each case an axial contact surface at which the two parts 11, 12 touch one another.
On the opposite side, the compression spring 28 is supported on a stop disk 29 which is inserted between the armature receptacle 6 and the cylinder part 7 of the pump casing 2.
On the side lying opposite the piston part 11, the magnetic part 12 has a recess 32, so that a web 15 is formed. A second compression spring 31 is supported on the recess 32, the compression spring 31 being held radially or centered by means of the web 15.
On the opposite side of the compression spring 31, the latter bears against a step 33 of the armature receptacle 6. The armature receptacle 6 comprises a stop 30 and is prolonged out of the coil 4 and forms at its end a connecting nipple 34 for the connection of a supply line.
The vibrating armature pump 1 operates as follows.
By the coil 4 being acted upon with alternating current or advantageously with pulsating or intermittent voltage without a change of sign, such as, for example, with an alternating voltage comprising only one (positive or negative) half wave (that is to say, the other half waves in each case are “faded out”, if appropriate, by means of a diode or the like), the pump piston 10 is set in vibration in the axial direction A. It in this case vibrates periodically about a neutral position defined by the compression springs 28, 31 and, if appropriate, also by the compression spring 18.
According to the invention, the two separate parts 11, lie only loosely one against the other during operation, without there being a firm or unreleasable connection. Only the two springs 28, 31 ensure that the two pump piston parts 11, 12 lie reliably one against the other without additional connection measures.
When the piston part 11 penetrates into the cylinder 13, the fluid located in the cylinder 13 is displaced. In this case, the sealing body 19 closes the outlet orifice of the axial passage 26 in the piston part 11. The fluid located in the cylinder 13 consequently attempts to pass through the through orifice 17 of the transverse web 16 into the connection piece 20, the sealing body 23 being pressed away from the through orifice 17, counter to the pressure of the compression spring 22, by the fluid which is put under pressure.
When the pump piston 10 vibrates back into the opposite direction, the piston part 11 is withdrawn from the cylinder 13. The remaining fluid located in the cylinder 13 is in this case depressurized and is subsequently put under a vacuum. The through orifice 17 is thereby closed by means of the compression spring 22 and the sealing body 23. The compression spring 22 and the sealing body 23 form a nonreturn valve, by means of which the backflow of the fluid which has just entered the region of the connection piece 20 is prevented.
During the withdrawal of the piston part 11, a vacuum is formed in the cylinder 13 and causes the sealing body 19 to lift off from the outlet of the axial passage 26, so that fluid flows through the passage 26 into the cylinder 13. The liquid or gaseous fluid passes via the inlet nipple 34 into the interior of the armature receptacle 6 and through the axial passage 27 of the magnetic part 12 to the axial passage 26 of the piston part 11.
After the cylinder 13 has been filled during the backward movement of the piston part 11, the fluid located in the cylinder 13 is once again displaced out of the cylinder 13 through the through orifice 17 during the forward movement of the piston part 11.
In the embodiment illustrated, the magnetic part 12 lies with its large cross section near the inner wall of the armature receptacle 6. However, the vibrating movement of the pump piston 10 necessitates the cyclical filling and emptying of the inner space of the armature receptacle 6 on both sides of the magnetic part 12. Since, in this embodiment of the magnetic part 12, there is only a very small gap between the magnetic part 12 and the inner wall of the armature receptacle 6, in this embodiment the transverse bore 25 is located in the intermediate region 24, so that an unimpeded fluid flow from one side of the magnetic part 12 to the other, and vice versa, is ensured.
However, the function of the transverse bore 25 may also be implemented in another way, for example by longitudinal bores or notches in the magnetic part 12. However, the present embodiment affords the advantage of a high magnetic mass in the region of action of the coil 4.
By the pump piston 10 being spring-mounted on both sides by means of the compression springs 28, 31, a cushioned reversal of movement takes place in the approach to each dead center during the axial movement, and therefore no hard stop occurs. Very quiet running of the pump is thus obtained. Furthermore, this arrangement constitutes a mechanically vibratory system, so that less energy is required from the coil 4 to keep the mechanical components of the vibrating armature pump in vibration.
By the compression springs 31, 28 being supported on the respective steps of the pump piston 10, the compression springs 28, 31 at the same time form, in conjunction with the extension 32 or the intermediate part 24 having a medium cross section, centering elements for the pump piston 10.
In a multipart version of the pump piston 10, furthermore, there is the possibility of a different choice of material between the magnetic part 12 and the piston part 11. The choice of material for the piston part 11 can therefore be selected with a view to the sealing function, the magnetic properties playing a minor role or even no role at all. For this part of the pump piston 10, therefore, magnetic or even nonmagnetic materials may be used, as required.
It is especially advantageous that a sufficiently high mass of magnetic material is arranged in the magnetic part 12 in the immediate region of action of the coil 4. The material of the magnetic part 12 does not in this case have to satisfy any appreciable properties in terms of leaktightness of the pump, and therefore, for example, a choice of material with a view to the efficiency or the power of the pump can be made at this point.
Furthermore, the two-part or multipart form of the pump piston 10 affords, in the region of the magnetic part 12, the possibility of simple manufacture, for example by cutting the magnetic part 12 to length from a tubular piece having an appropriate diameter and an axial passage 27 and composed of suitable magnetic or magnetizable material.
The pump according to the invention is therefore a piston pump 1 with an electromagnetic drive 4. Single-wave rectification, not illustrated in any more detail, is especially advantageous for operating the pump 1. An advantageous rectifier, in particular a diode or the like, is preferably already integrated into the pump 1, so that a generally conventional alternating voltage can advantageously be applied to the coil terminals. In the case of an advantageous alternating voltage with a frequency of, for example, f=50 Hz, 50 voltage halfwaves are generated per second by means of the rectifier.
An advantageous voltage halfwave gives rise in the pump 1, above all, to the following processes:
a) magnetic action upon the pump piston 10:
the current flowing through the coil 4 when a voltage halfwave is applied generates in the coil 4 a magnetic field which acts as electromagnetic force upon the piston 10 (large diameter) and counter to the piston spring 31.
In order to achieve as high a magnetic force action as possible, the coil 4 is preferably surrounded by a ferromagnetic circuit. This ferromagnetic circuit is advantageously interrupted in the region of the piston side against which the piston spring 31 acts by an air gap having a length of a few millimeters. The two iron parts which may form the air gap are referred to, for example, as pole sleeves and the remaining ferromagnetic circuit is referred to as a box-type yoke plate.
As soon as the current begins to flow and the magnetic action of the coil field becomes greater than the force with which the piston 10 is held in the position of rest, the piston 10 moves in the direction of the air gap. In an advantageous exemplary embodiment, this piston stroke in the direction of the piston spring amounts, for example, to approximately 6 to 7 mm. As soon as the current (halfwave) and therefore the magnetic force action upon the piston 10 falls or the piston 10 has largely bridged the air gap, the piston spring 31 is also tensioned to the maximum.
After the magnetic force action of the coil 4 has largely fallen, the piston 10 moves in the direction of the piston position of rest again on account of the force action of the piston spring 31. The kinetic energy of the piston 10 is so high that the piston 10 moves further along beyond the position of rest and is then advantageously braked by the damping spring 28. For example, this damped stroke amounts to approximately 3 to 4 mm. The damping spring 28 subsequently moves the piston 10 back in the direction of the piston position of rest again and settles into the position of rest again as a function of frictional and fluid damping.
b) pumping action, for example, without counterpressure
The piston 10 has a large and a small diameter. The large diameter is used to bring about force action in the direction of the air gap by means of a magnetic field. The small diameter serves as a hydraulic pressure piston 11.
The hydraulic pressure piston 11, in the position of rest, projects approximately 8 mm into a compression chamber. This hydraulic pressure piston 11 is advantageously hollow 26 or drilled open in the middle. This bore 26 is closed in turn by means of a valve 19 and a compression spring 18 (long).
When the piston 10 is moved on account of the electromagnetic force, the water located behind the piston 10 (the same side as the piston spring) is advantageously pressed through the large piston bore 27 and subsequently through the small piston bore 26. During this action, the valve 19 enclosing the small piston bore 26 opens and the compression chamber is filled with water.
As soon as the piston stroke has reached maximum and the piston 10 begins to move in the opposite direction again on account of the force of the piston spring 31, the valve 19 located on the piston 10 closes, so that the pressure piston 11 penetrating into the compression chamber displaces with its increasing volume the water which is located there. On account of this displacement process, the valve 23 located at the pump outlet opens and the water emerges from the pump 1.
Since the piston 10, on account of its kinetic energy, can move further on beyond the position of rest, for example, because of the damping spring 28, this piston volume penetrating into the compression chamber will also additionally displace water.
As soon as the damping spring 28 moves the piston 10 in the direction of the position of rest again, the valve 23 at the outlet (short spring 22) closes and the valve 19 on the piston 10 (long spring 18) opens, so that the compression chamber is filled with water again and the process is repeated as long as voltage halfwaves are applied to the coil 4.
c) pumping action in the case of a counterpressure of, for example, p=12 bar:
As soon as the throughflow is reduced on the pump outlet side, for example, by means of a throttle, a corresponding counterpressure builds up at the pump outlet. This counterpressure has the effect that the piston 10 is displaced out of its position of rest at p=0 bar.
The displacement of the piston 10 is determined by the surface of the pressure piston 11, the pressure acting on the pressure piston surface and the counteracting force of the piston spring 31. The higher the counterpressure, the more the piston 10 is displaced out of its position of rest at p=0 bar. As a result, the air gap is reduced and the pretension of the piston spring 31 (action of force of the spring 31 in the position of rest) becomes greater. Since the air gap has become smaller and at the same time the spring force greater, when the electrical halfwave is applied, the piston stroke is no longer, for example, 6 mm to 7 mm, as at p=0 bar, but is substantially smaller.
The result of the smaller piston stroke is that less water is displaced in the pressure chamber. When the throttle is closed completely, the piston 10 is moved further out of the position of rest during each pump stroke until the electromagnetic force no longer enables the piston spring 31 to be tensioned, and the piston 10 finally comes to a standstill.
List of Reference Symbols
1 Vibrating armature pump
2 Pump casing
3 Yoke
4 Coil
5 Contact
6 Armature receptacle
7 Cylinder part
8 Flange
9 Annular shoulder
10 Pump piston
11 Piston part
12 Magnetic part
13 Cylinder
14 Web
15 Web
16 Transverse web
17 Through orifice
18 Compression spring
19 Sealing body
20 Connection piece
21 Supporting ring
22 Compression spring
23 Sealing body
24 Intermediate part
25 Transverse bore
26 Axial passage
27 Axial passage
28 Compression spring
29 Stop disk
30 Stop
31 Compression spring
32 Recess
33 Step
34 Connecting nipple

Claims

1. A vibrating armature pump with a pump casing (2), which comprises a cylinder (13) for receiving a pump piston unit (10) adjustable essentially linearly, characterized in that the pump piston unit (10) has at least one separate pump element (11) for pumping the pump fluid and one separate drive element (12) for driving the pump element (11).

2. The vibrating armature pump as claimed in claim 1, characterized in that the pump element (11) has a first stop (5) for the drive element (12) and the drive element (12) has a second stop (5) for the pump element (11).

3. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least one first spring element (28) is provided for acting with force upon the pump piston unit (10) and/or the pump element (11).

4. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least one second spring element (31) is provided for acting with force upon the pump piston unit (10) and/or the drive element (12), the spring force of the second spring element (31) being directed opposite to the spring force of the first spring element (28).

5. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least the drive element (12) is composed essentially of a ferromagnetic material.

6. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least the drive element (12) is composed essentially of high-grade steel.

7. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least the pump element (11) is composed essentially of a plastic.

8. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that at least one coil (4) is provided for adjusting the drive element (12).

9. The vibrating armature pump as claimed in one of the abovementioned claims, characterized in that a pulsating or intermittent voltage is provided.