DIAPHRAGM PUMP AND METHOD FOR CONTACTLESS ACTUATION THEREOF

Abstract

Depicted and described herein is a diaphragm pump (1) for conveying a gaseous and/or liquid medium, having at least one deformable membrane (2) for changing the size of a work chamber (3) of the diaphragm pump (1), and having at least one actuating unit (4) for deforming the membrane (2) by means of applying contact-free force to the membrane (2) using a magnetic field, wherein the membrane (2) comprises and/or consists of a material which is magnetic and/or magnetizable, and the actuating unit (4) features at least one magnetic and/or magnetizable actuating means (7). According to the invention, the actuating unit (4) is rotatably mounted and the membrane (2) is arranged circumferentially with respect to the actuating unit (4), wherein, in a dead point position of the membrane (2), the polarization direction of the magnetic field generated between the material of the membrane (2) and the actuating means (7) is oriented in a direction radial to the axis of rotation of the actuating unit (4).

Claims

1-11. (canceled)

12. A diaphragm pump for conveying a gaseous, liquid, or gaseous/liquid medium, comprising: at least one deformable membrane for changing the size of a work chamber of the diaphragm pump; and at least one actuating unit for deforming the membrane by applying contact-free force to the membrane using a magnetic field, wherein the membrane comprises or consists of a material which is magnetic or magnetizable, and the at least one actuating unit includes at least one magnetic or magnetizable actuating means.

13. The diaphragm pump of claim 12, wherein the actuating unit is rotatably mounted and the membrane is arranged circumferentially with respect to the actuating unit; and wherein, in a dead point position of the membrane, the polarization direction of the magnetic field generated between the material of the membrane and the actuating means is oriented in a direction radial to the axis of rotation of the actuating unit.

14. The diaphragm pump of claim 12, wherein an axis of rotation of the actuating unit is arranged at an offset and parallel to a membrane central axis on the membrane such that, upon rotation of the actuating unit, the actuating means moves cyclically past the membrane and cyclically crosses over the membrane.

15. The diaphragm pump according to claim 12, wherein the actuating unit includes multiple magnetic poles of number (n) having opposite polarization and acting on the membrane; and wherein each magnetic pole group consists only of magnetic poles having the same polarization, and wherein (n) is greater than or equal to two and the magnetic poles are generated by means of one or multiple actuating means.

16. The diaphragm pump according to claim 15, wherein the magnetic poles or magnetic pole groups of the actuating unit having opposite polarization are arranged successively in the direction of rotation of the actuating unit, wherein the magnetic poles or magnetic pole groups are arranged at an offset of 360/n to one another in the direction of rotation of the actuating unit.

17. The diaphragm pump according to claim 15, wherein multiple work chambers of number (m) are provided, wherein each work chamber is associated with a membrane, wherein (m) is preferably greater than or equal to (n), and wherein the work chambers are arranged at an offset of 360/m to one another in the direction of rotation of the actuating unit.

18. The diaphragm pump of claim 12, wherein a magnetic field is generated between the material of the membrane and the actuating means, wherein the actuating unit is rotatably mounted, and a stator unit is provided for generating a rotating magnetic field, wherein the rotating magnetic field generated by the stator unit is designed to drive the actuating unit in a rotary manner.

19. The diaphragm pump of claim 12, wherein a magnetic field is generated between the material of the membrane and the actuating means, and wherein the work chamber is arranged between the actuating means and the membrane.

20. The diaphragm pump according to claim 12, wherein at least two work chambers are provided, wherein each work chamber is associated with a separate pump head.

21. The diaphragm pump according to claim 20, wherein the at least one deformable membrane comprise multiple membranes arranged successively in the direction of rotation of the actuating unit that are able to be deformed in a contact-free manner using the actuating means; and wherein at least two work chambers of the diaphragm pump are associated with a common pump head.

22. The diaphragm pump of claim 20, wherein a magnetic field is generated between the material of the membrane and the actuating means, wherein the at least two work chambers are arranged at an offset of 160 to 200 to one another in the direction of rotation of the actuating unit, wherein the membranes of the work chambers on the actuator side feature different magnetic poles, and wherein the actuating unit on the membrane side includes at least two different magnetic poles arranged at an offset of 160 to 200 to one another in the direction of rotation of the actuating unit.

23. A method for applying contact-free force to the membranes of the work chambers of a diaphragm pump used for conveying a gaseous, liquid, or liquid/gaseous comprising a diaphragm pump of claim 20, wherein the membranes of the at least two work chambers are deformed free of contact by means of force applied using a magnetic field, wherein the magnetic field is generated between the membranes and at least one magnetic or magnetizable actuating means of a rotatable actuating unit, and wherein membranes arranged successively in the direction of rotation of the actuating unit are deformed in a contact-free manner by means of magnetic interaction with the actuating means.

Description

[0058] The invention will be explained hereinafter in connection with the drawings and in reference to preferential embodiments. Shown are:

[0059] FIG. 1 a perspective view of a diaphragm pump according to the invention as specified by a first embodiment,

[0060] FIG. 2 a cross-sectional view of the diaphragm pump from FIG. 1 along the section line II-II,

[0061] FIG. 3 an exploded perspective depiction of a diaphragm pump according to the invention as specified by a second embodiment,

[0062] FIG. 4 a further exploded perspective depiction of the diaphragm pump according to the invention from FIG. 3,

[0063] FIG. 5 a cross-sectional view of the diaphragm pump from FIG. 3 along the section line V-V from FIG. 4,

[0064] FIG. 6 an exploded perspective depiction of a diaphragm pump according to the invention as specified by a third embodiment,

[0065] FIG. 7 a cross-sectional view of the diaphragm pump from FIG. 6,

[0066] FIG. 8 a perspective view of a diaphragm pump according to the invention as specified by a further embodiment,

[0067] FIG. 9 a first cross-sectional view of the diaphragm pump from FIG. 8 along the section line IX-IX,

[0068] FIG. 10 a second additional cross-sectional view of the diaphragm pump from FIG. 8 along the section line X-X, and

[0069] FIG. 11 an exploded perspective view of the diaphragm pump from FIG. 8.

[0070] FIGS. 1 and 2 show a diaphragm pump 1 for conveying a gaseous and/or liquid medium (not depicted). The diaphragm pump 1 has multiple (four in the example depicted) deformable diaphragms 2 for changing the size of four work chambers 3 of the diaphragm pump 1.

[0071] A pumping process consists of a suction phase and a compression phase, with the medium being drawn into an expanding work chamber 3 during the suction phase and then discharged from a shrinking work chamber 3 during a compression or pressure phase. In this context, the membranes 2 for enlarging or shrinking the size of the work chamber 3 are at least partially deformable, in particular elastic.

[0072] The diaphragm pump 1 features an actuating unit 4, which is rotatably mounted or driven, to deform the membranes 2 (see FIG. 2). A drive device 5, preferably an electric motor, is provided to drive the actuating unit 4. The deformation of the membranes 2 takes place by means of applying contact-free force using a magnetic field, whereby the membranes 2 comprise or consist of a material which is magnetic or magnetizable. In the example depicted, each membrane 2 features a permanent magnet as a magnetic means 6, which is embedded into or accommodated in a central area of the membrane 2. In this context, the magnetic means 6 of all membranes 2 preferably have the same polarity as the actuating unit 4.

[0073] In the example depicted, the actuating unit 4 features only one actuating means 7, which is designed as a diametrically magnetized ring magnet with two magnetic poles of opposite polarization. In this respect, the actuating unit 4 features a receiving portion 4a, which spans circumferentially and in which the actuating means 7 is accommodated and supported. The actuating unit 4 can in particular be of multi-piece design in order to allow the actuating means 7 to slide onto the receiving portion 4a. In particular, the actuating unit 4 consists of two components able to be screwed or inserted together, each of which features a radial projection and between which the actuating means 7 is supported in an axial direction on the receiving portion 4a. However, other design solutions are also possible.

[0074] In order to deform the membranes 2 in a contact-free manner, a magnetic field (not depicted), which is oriented in a direction radial to an axis of rotation 8 of the actuating unit 4, is generated between the actuating means 7 on the one hand and the magnetic means 6 of the associated membrane 2 on the other.

[0075] The actuating unit 4 in the embodiment depicted in FIG. 2 is designed to be sleeve-shaped or wave-shaped.

[0076] In the embodiment depicted, the two outer magnetic poles of the actuating means 7 are arranged at an offset of 180 to one another in the actuating unit 4 direction of rotation, and the four work chambers 3 are arranged at an offset of 90 to one another in the direction of rotation of the actuating unit 4.

[0077] As is evident from FIG. 2 in particular, the membranes 2 having the associated work chambers 3 are arranged within the longitudinal dimension of the actuating unit 4.

[0078] Shown in FIG. 2 is a rotational position of the actuating unit 4 where the membranes 2 of two work chambers 3 located opposite are simultaneously deformed due to the magnetic field. In this context, the membrane 2 of a first, upper work chamber 3 (shown in FIG. 2) is repelled by the south pole S of the actuating means, or rather ring magnets, and pushed into an inner dead point position (not shown), whilst the membrane 2 of a second, lower work chamber 3 (shown in FIG. 2) is attracted by the north pole N of the ring magnet, or rather actuating means 7, and pushed into an outer dead point position (not shown). The magnetically repelled membrane 2 and the magnetically attracted membrane 2 are arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4. The membranes 2 of the two other work chambers 3 are in this rotational position of the actuating unit 4 subject to at most a small magnetic interaction with the actuating unit 7 and are situated in a non-deformed resting position. This is due to the fact that the magnetic means 6 of this membrane 2 in the rotational position of the actuating unit 4 shown (see FIG. 4, Regions 7c) are located opposite regions which are designed to be non-magnetic or only weakly magnetic. Accordingly, no magnetic interaction or at most a small magnetic interaction takes place between the magnetic means 6 and these regions of the actuating unit 4.

[0079] Upon rotation of the actuating unit 4 (as per FIG. 2), the membranes 2 of the work chambers 3 consecutively arranged in the direction of rotation of the actuating unit 4 are consecutively actuated in a contact-free manner by means of the moving magnetic poles of the actuating unit 4. Preferably, no rotational position of the actuating unit 4 will result in the membranes 2 of all work chambers 3 being simultaneously situated at an equal inner or outer dead point, or result in all of them being simultaneously situated at an equal non-deflected or weakly deflected position between the dead points. For example, at a certain rotational position of the actuating unit 4, only the membrane 2 of a first work chamber 3 can be situated in an inner dead point position, only the membrane 2 of a second work chamber 3 can be situated in an outer dead point position, and the membranes 2 of a further work chamber 3 can be situated in a preferably non-deflected or only slightly deflected position between the dead points, which is reached during the suction phase or the compression phase. Very low-pulsation operation of the diaphragm pump 1 according to the invention is made possible in this way. The course of movement of the membranes 2 lends itself to description as a sine curve, in which context the course of movement of the membranes 2 of the four work chambers 3 can be described as four sine curves offset in opposition to one another, while the courses of movement of the membranes 2 overlap. As a consequence, the membrane movement cycle can be rendered in idealized fashion as a sine curve.

[0080] As is not shown, the two membranes 2 (depicted at the left and right of FIG. 2) located opposite in relation to the outer side facing the actuating unit 4 can also have the opposite polarity as one another or feature different magnetic poles. As a result of this, upon rotational movement of the actuating unit 4, the membranes 2 of both work chambers located opposite are pushed into either an inner dead point position or into an outer dead point position by means of the magnetic poles of the actuating unit 4. This can have the result of the magnetic forces and/or moments acting on the actuating unit 4 cancelling each other out such that the mechanical load on the actuating unit 4 is accordingly reduced.

[0081] In the embodiment depicted, a separate pump head 9 is provided for each membrane 2. The pump heads 9 are correspondingly arranged at an offset of 90 to one another in the direction of rotation of the actuating unit 4. The pump heads 9 each feature an inner housing portion 10 and an outer housing portion 11. Formed in the inner housing portion 10 is a chamber wall 12, the top of which borders the corresponding work chamber 3.

[0082] The diaphragm pump 1 features an actuator housing 13 for accommodating the actuating unit 4. The pump heads 9 are screwed onto the actuator housing 13, whereby the edge portion of the membranes 2 can be fixed to form a seal between the actuator housing 13 on the one hand and the pump heads 9 on the other.

[0083] Each pump head 9 can feature valves (see FIG. 5), preferably non-return valves, in order to prevent the medium from being discharged through an inlet during the compression phase or being drawn in through an outlet during the suction phase (see FIG. 4, Inlet 17, Outlet 18).

[0084] The drive apparatus 5 is also screwed onto the actuator housing 13. The drive apparatus 5 features a flange plate 14 for this purpose. The actuating unit 4 is non-rotatably arranged on a driving shaft 15 of the drive apparatus 5.

[0085] Arranged on each chamber wall 12 are at least one inlet and at least one outlet (see FIG. 4, Inlet 17, Outlet 18). The medium is drawn into the work chamber 3 through the inlet during the suction phase and expelled from the work chamber 3 through the outlet during the compression phase.

[0086] The medium to be conveyed is drawn into the diaphragm pump 1 through a suction line 19. The medium is led through the suction line 19 and into an inlet collecting chamber 20, whereupon the medium is fed from the inlet collecting chamber 20 to the inlets of the respective work chambers 3. Furthermore provided is an outlet collecting chamber 21, where the medium expelled from the work chambers 3 through the outlets is collected and accommodated before leaving the diaphragm pump 1 through a pressure line 22. In the example depicted, the inlet collecting chamber 20 and the outlet collecting chamber 21 are arranged at the front of the actuating unit 4 and opposite the drive apparatus 5. The inlet collecting chamber 20 and the outlet collecting chamber 21 are formed by a preferably multi-piece collecting housing 23, with a separate housing portion being provided for each collecting chamber 20, 21. The collecting housing 23 is screwed onto the actuator housing 13. The drive apparatus 5, the actuator housing 13, and the collecting housing 23 are located one after the other in the direction of the axis of rotation 8 of the actuating unit 4, thus resulting in a compact design.

[0087] Alternative embodiments of diaphragm pumps 1 are depicted in FIGS. 3 to 11. Components of the diaphragm pumps having the same function are described using the same reference signs.

[0088] It is evident from FIGS. 3 to 5 that a drive apparatus 5, an actuator housing 13, and a pump head 9 are in this embodiment arranged axially one after the other in the direction of the axis of rotation 8 of an actuating unit 4, and they are screwed together.

[0089] The pump head 9, the actuator housing 13, and the flange plate 14 feature an identical outer contour. In particularapart from fluid or electrical connectionsno components are provided which project beyond this outer contour. This enables the diaphragm pump 1 to have a compact and, in particular, flat design.

[0090] The actuating unit 4 in this embodiment is designed as a rotating disc or to be plate-shaped, in which case the actuator housing 13 features a corresponding disc-shaped recess 24, in which the actuating unit 4 is accommodated (see FIG. 4).

[0091] In the embodiment depicted, a common pump head 9 is provided for all four work chambers 3. The pump head 9 features a cover 25, which features the suction line 19 and the pressure line 22 (see FIG. 3). The pump head 9 furthermore features an inner housing portion 10 and an outer housing portion 11. Each work chamber 3 is bordered by a chamber wall 12 of the inner housing portion 10 and by a membrane 2. Each membrane 2 features a magnetic means 6.

[0092] The actuating unit 4 as per FIG. 4 features, inserted on the front side, two actuating means 7, which are each formed by a group of permanent magnets 7a, 7b having the same outward polarization. The actuating means 7, or rather the permanent magnets 7a, 7b arranged in group fashion, are arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4. Regions 7c, which are designed to be non-magnetic or at most weakly magnetic, are provided between the permanent magnets 7a, 7b in a circumferential direction or rather the direction of rotation of the actuating unit 4.

[0093] The front side of the actuating unit 4 facing the drive apparatus 5 otherwise features a bore 26 corresponding to a driving shaft 15 of the drive apparatus 5. The actuating unit 4 is non-rotatably connected to the driving shaft 15. Moreover, a circular depression 27 for accommodating a circular projection 16 of the drive apparatus 5 is provided on said front side of the actuating unit 4. Reliable mounting of the actuating unit 4 is ensured in this way.

[0094] As is evident from FIG. 5, an inlet collecting chamber 20 and an outlet collecting chamber 21 are formed by the outer housing portion 11 of the pump head 9. The collecting chambers 20, 21 are closed on the top by the cover 25 of the pump head 9.

[0095] The pump head 9 features valves 28 (only hinted at in the depiction), in particular non-return valves. The medium is thereby prevented from being expelled through an inlet 17 during the compression phase and being drawn in through an outlet 18 during the suction phase. The valves 28 are preferably arranged between the inner housing portion 10 and the outer housing portion 11.

[0096] As is also evident from FIG. 5, the membranes 2 having the associated work chambers 3 are arranged (immediately) opposite a front side of the actuating unit 4. The membranes 2 are essentially arranged on a common plane. Shown in FIG. 5 is a rotational position of the actuating unit 4 where the membranes 2 of two work chambers 3 arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4 are simultaneously deformed due to the existing magnetic field.

[0097] The central axes M of the membranes 2 run at a lateral offset to the axis of rotation 8 of the actuating unit 4. The magnetic means 6 of the membranes 2 are in this case centrally arranged in the area of the membrane axis M. Upon rotation of the actuating unit 4, the actuating means 7 of the actuating unit 4 are led along a circular path past the magnetic means 6 of the membranes 2, which causes the cylic deflection of the membranes 2.

[0098] As per FIG. 5, the membrane 2 of a first work chamber 3 (depicted at left in FIG. 5) is repelled by the south pole of a permanent magnet 7a of the first actuating means 7 and pushed into an inner dead point position (not shown), whilst the membrane of a second work chamber 3 (depicted at right in FIG. 5) is attracted by the north pole of a permanent magnet 7b of the second actuating means 7 and pushed into an outer dead point position (not shown). In order to achieve pulsation-free operation of the diaphragm pump 1, it is provided that, in said rotational position of the actuating unit 4, the membranes 2 of the two other work chambers 3 are subject to a slight magnetic interaction since, in the rotational position of the actuating unit 4 shown, they are arranged opposite regions 7c designed to be non-magnetic or at most weakly magnetic.

[0099] The magnetic means 6 of two membranes 2 arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4 or rather located opposite (such as the magnetic means 6 of the membranes 2 depicted at left and right in FIG. 5), can also differ from FIG. 5 on the actuator side and have opposite polarity or differently named magnetic poles. In this case, the magnetic means 6 are arranged such that the membrane 2 of a work chamber 3 features a south pole on the side (externally) of the actuating unit 4, and the membrane 2 of the opposite work chamber 3 features a north pole on the side of the actuating unit 4. At a certain rotational position of the actuating unit 4, the membranes 2 located opposite are then simultaneously attracted to the actuating unit 4 or repelled by the actuating unit 4 or, rather, the membranes 2 located opposite are simultaneously situated at an inner dead point position or an outer dead point position. The result thereby can be that the magnetic forces on both sides of the actuating unit 4 axis of rotation 8 acting on the actuating unit 4 can be balanced, thus reaching a torque equilibrium. Imbalances which can lead to vibrations and increased wear can thus be avoided.

[0100] A further, alternative embodiment of a diaphragm pump will be described hereinafter in reference to FIGS. 6 and 7. As is not depicted, a pump head is provided which, together with four membranes 2 fixed between the pump head and an actuator housing 13, forms four work chambers. The design of the pump head can correspond to the embodiment shown in FIGS. 3 to 5.

[0101] In this embodiment, a drive apparatus 5 for an actuating unit 4 is provided which is designed as a plate-shaped stator unit 29 having a plurality of coils 30. The coils 30 are preferably arranged in the stator unit 29 concentrically and offset at regular intervals from one another in the direction of rotation of the actuating unit 4. The diaphragm pump 1 features control electronics (not shown) designed for controlling the polarity changes of the coils 30. The rotational position of the actuating unit 4 is detected thereby, in which case the change in polarity of the coils 30 used to generate a rotating magnetic field depends on said rotational position. The driving of or rotation of the actuating unit 4 then takes place as a result of the rotating magnetic field generated by the coils 30.

[0102] The stator unit 29 is preferably designed for rotatably mounting the actuating unit 4. A bearing bore 31, preferably centrally arranged, is provided for this purpose. Accordingly, the actuating unit 4 features a centrally arranged bearing journal 32, which is in particular able to fit precisely into the bearing bore 31. The stator unit 29 is connected to an actuator housing 13.

[0103] The embodiment depicted furthermore provides two actuating means 7, which are each in the form of axially magnetized permanent magnets having the circular shape of a segment of a ring. The actuating means 7 are arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4 and preferably extend across 90 in the direction of rotation of the actuating unit 4. Doing so enables an effective magnetic interaction with the stator unit 29 and a high degree of efficiency for the diaphragm pump 1.

[0104] The actuating means 7 are an integral part of the actuating unit 4 and complement it circumferentially and on the front side to form a disc shape, as is particularly clear from FIG. 6. On a front side of the actuating unit 4 facing away from the drive unit 5, the actuating means 7 each generate a magnetic pole N, S for acting on the membrane 2 located opposite, as well as a magnetic pole N, S of opposite polarization on the other front side of the actuating unit 4 for interacting with the stator unit 29. Referring to FIG. 7, it is also the case in this embodiment that the membranes 2 are arranged opposite the front side of the actuating unit 4 and are essentially horizontally arranged on a common plane.

[0105] In order to enable low-pulsation operation of the diaphragm pump 1, the membrane 2 of a work chamber (arranged at left in FIG. 7) is, in a certain rotational position of the actuating unit 4 (shown in FIG. 7), attracted by the north pole N of the first actuating means 7, which has the shape of a segment of a ring, and pushed into an outer dead point position (not shown), whilst the membrane 2 of a work chamber (arranged at right in FIG. 7) is repelled by the south pole S of the second actuating means 7, which has the shape of a segment of a ring, and pushed into an inner dead point position (not shown). In a certain rotational position of the actuating unit, the magnetically repelled membrane 2 and the magnetically attracted membrane 2 are arranged at an offset of 180 to one another. In said certain rotational position, the membranes 2 of two further work chambers are associated with non-magnetized or at most weakly magnetized regions 7c and are thus situated in a non-deformed position between the dead point positions. Similar to the previous embodiments, at no point in time, hence at no rotational position of the actuating unit 4, will the membranes 2 of all work chambers be simultaneously situated at an equal inner or outer dead point position, or at an equalpreferably non-deflected or weakly deflectedposition between the dead point positions. At said certain rotational position of the actuating unit 4, preferably only the membrane 2 of a first work chamber is situated in the inner dead point position, only the membrane 2 of a second work chamber is situated in the outer dead point position, and the membranes 2 of two further work chambers can be situated in a preferably non-deformed or only slightly deformed position, which is reached during the suction phase or the compression phase and lies between the dead point positions. Corresponding advantages are able to be realized in this way.

[0106] Another alternative embodiment of the diaphragm pump 1 will be described in reference to FIGS. 8 to 11. Not shown is a drive apparatus for driving the actuating unit 4. According to the embodiments previously described, the drive apparatus can be designed as an electric motor or as a brushless DC motor.

[0107] As is evident from FIG. 8, the diaphragm pump 1 features an actuator housing 13, an inner housing portion 10, as well as an outer housing portion 11. With respect to an axis of rotation 8 of the actuating unit 4 (FIG. 9), the actuator housing 13, the inner housing portion 10, as well as the outer housing portion 11 are arranged one after the other in an axial direction, and they are screwed together. The drive apparatus is preferably secured to the actuator housing 13. The actuator housing 13 features for this purpose corresponding connecting means, in particular threaded and/or receiving bores (schematically indicated in FIG. 8). In particular, the actuator housing 13 features a throughgoing bore 13a, through which a driving shaft of the drive apparatus can be inserted in order to drive the actuating unit 4.

[0108] The actuator housing 13, the inner housing portion 10, and the outer housing portion 11 feature an outer contour that is very nearly complementary and corresponding, in particular rectangular or square.

[0109] In the embodiment depicted, four separate pump heads 9 are provided, each of which is arranged and secured on an outer side of the housing of the diaphragm pump 1. Each pump head 9 has a suction line 19 and a pressure line 22, with the fluid to be conveyed being drawn into the pump head 9 through the suction line 19 and conveyed out of the pump head 9 through the pressure line 22.

[0110] The membranes 2 are fixed edgewise between the inner housing portion 10 and the outer housing portion 11 (see FIG. 9). The actuating unit 4 is designed as a rotating disc in this embodiment as well. Each membrane 2 furthermore features a magnetic means 6, for example in the form of a permanent magnet. Each work chamber 3 is bordered by both a chamber wall 12 and the membrane 2, in which case the chamber wall 12 is formed by an area of the inner housing portion 10. The actuating unit 4 features actuating means 7, which are designed as permanent magnets 7a, 7b arranged in group fashion (as per FIG. 4). The unequal magnetic poles or rather magnetic pole groups generated on the membrane side by the permanent magnets 7a, 7b are arranged at an offset of 180 to one another in the direction of rotation of the actuating unit 4. As shown for the embodiment in FIG. 4, regions that are designed to be non-magnetic or at most weakly magnetic are provided between the permanent magnets 7a, 7b in a circumferential direction or rather the direction of rotation of the actuating unit 4.

[0111] The work chambers 3 are arranged between the membranes 2 and the permanent magnets 7a, 7b of the actuating unit 4. In terms of structure, the membranes 2 are separated from the actuating unit 4 and thus from the actuating means 7 by the chamber walls 12 of the inner housing portion 10. At least in the area of the chamber walls 12, the inner housing portion 10 consists of a material, for example a plastic material, which does not resist the magnetic coupling between the actuating means 7 and the magnetic means 6 of the membrane 2 and permits contact-free deformation of the membranes 2 by the actuating means 7.

[0112] In all of the embodiments shown and described, the membranes 2 can feature a round, preferably circular, outer contour. The magnetic means 6, which are preferably cylindrical, are arranged and supported in a central area of the membranes 2 or in the area of the central axes M. In order to prevent contact between the magnetic means 6 and a fluid being conveyed, the magnetic means 6 can be arranged on a side of the membrane 2 facing away from the work chamber 3. For this purpose, the central areas of the membranes 2 can be designed with added thickness in comparison to the edge areas thereof, in which case the membranes can be designed to have depressions or receiving portions for the magnetic means 6. The magnetic means 6 are then mounted on the membranes 2 by means of sliding the magnetic means 6 into the receiving portions and, optionally, by means of gluing.

[0113] The embodiment shown in FIGS. 8 to 11 is advantageous in that contact between the actuating means 7 of the actuating unit 4 and the magnetic means 6 of the membranes 2 during operation of the diaphragm pump 1 is reliably precluded. This results in a significant reduction of unwanted noise during operation of the diaphragm pump 1.

[0114] It should be noted that the edge areas of the membranes 2 are preferably designed to have thin walls in order to enable easy deformability. Preferably, only the edge areas of the membranes 2 are deformed during pump operation, whereas the central areaswhich are strengthened by the rigid magnetic means 6retain essentially the same shape.

[0115] The pump heads 9 are connected to the sides of the work chambers 3 in a lateral direction (see FIG. 10). Each pump head 9 features a baseplate 33 and a head portion 34. The suction line 19 and the pressure line 22 are formed by the head portion 34. The baseplate 33 is arranged on, in particular screwed onto, the actuator housing 13 and the outer housing portion 11. Valves 28 in the form of an inlet valve 35 and an outlet valve 36 are provided between the baseplate 33 and the head portion 34 (see FIG. 11).

[0116] During pump operation, the fluid to be conveyed is drawn in through the suction line 19 of a pump head 9 during the suction phase. After passing through the inlet valve 35, the fluid continues into the work chamber 3 via the inner housing portion 10. The fluid is likewise expelled from the work chamber 3 via the inner housing portion 10 during the compression phase.

[0117] It is further evident from FIG. 11 that the actuating unit 4 features a plurality of preferably cylindrical recesses 37, which are arranged consecutively in the direction of rotation and into which the magnets 7a, 7b are inserted.

[0118] It is understood that the previously described embodiments are not limited to the design of the diaphragm pump 1 having four work chambers 3. Moreover, the features of the previously described embodiments may be combined with one another as necessary, even if this fact is not explicitly described or shown in detail.

TABLE-US-00001 List of reference signs: 1 Diaphragm pump 2 Membrane 3 Work chamber 4 Actuating unit 4a Receiving portion 5 Drive apparatus 6 Magnetic means 7 Actuating means 7a Magnet 7b Magnet 7c Region 8 Axis of rotation 9 Pump head 10 Housing portion 11 Housing portion 12 Chamber wall 13 Actuator housing 13a Throughgoing bore 14 Flange plate 15 Driving shaft 16 Projection 17 Inlet 18 Outlet 19 Suction line 20 Inlet collecting chamber 21 Outlet collecting chamber 22 Pressure line 23 Collecting housing 24 Recess 25 Cover 26 Bore 27 Depression 28 Valve 29 Stator unit 30 Coil 31 Bearing bore 32 Bearing journal 33 Baseplate 34 Head portion 35 Inlet valve 36 Outlet valve 37 Recess