Diaphragm pump

Abstract

To provide a diaphragm pump improved in the residual emptying and / or the venting of pumping chambers.SOLUTION: A diaphragm pump has at least one pump chamber. The pump chamber is connected to an inlet chamber 12 via an inlet valve 22 and to an outlet chamber 14 via an outlet valve 24. The inlet valve has an inlet opening which can be closed by an inlet valve body, and the outlet valve has an outlet opening which can be closed by an outlet valve body. The outlet opening surrounds the inlet opening, or the inlet opening surrounds the outlet opening.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The invention relates to a diaphragm pump which comprises a pumping chamber which is connected via an inlet passage to an inlet chamber and via an outlet passage to an outlet chamber. [Background technology]

[0002] The diaphragm pump known from DE 10117531 A1 and DE 202006020237 A1 primarily comprises a pump head connected to a drive. The pump head has a number of, for example, four pump chambers, which are each sealed off from the drive chamber by means of pump diaphragms. Each pump diaphragm is connected via a correspondingly arranged pump element to a swash plate arranged in the drive chamber. The oscillating movement of the swash plate then causes the pump diaphragm to perform a periodic axial oscillating pumping movement. The swash plate is mounted on a drive journal of a drive shaft connected to the drive. The drive journal is inclined with respect to the longitudinal axis of the drive shaft and is connected to the swash plate via a ball bearing. In the diaphragm pumps described in DE 10117531 A1 and DE 202006020237 A1, the outlet chamber is arranged centrally and the inlet chamber is arranged around the outlet chamber concentrically with respect to the outlet chamber.

[0003] DE 10 2008 035 592 A1 discloses a diaphragm pump in which an inlet chamber is arranged centrally and an outlet chamber is arranged concentrically relative to the inlet chamber, the outlet chamber has an outlet passage in its vertically lower area, the pump chamber and a valve plate with a valve are arranged between an intermediate plate part with these chambers and a diaphragm support part supporting the pump diaphragm, and an inlet valve plate with an inlet valve is arranged in front of the inlet chamber of the intermediate plate part in a step of the valve plate towards the pump chamber.

[0004] Such pumps are used in particular in the fields of chemistry, pharmacy and biotechnology, where the medium to be pumped is sometimes very expensive, so that it is desirable that after the pumping operation, no or only a small residual amount of the pumped medium remains in the diaphragm pump as far as possible.Furthermore, it is advantageous for the pumping power to completely fill such a diaphragm pump with fluid without the ingress of air bubbles.

[0005] The disadvantages of the diaphragm pumps known from DE 10117531 A1 and DE 202006020237 A1, which have proven to be basically successful, are that they have a central inlet chamber, which, due to the outer outlet chamber arranged substantially concentrically with respect to the inlet chamber, leads to a situation in which a relatively large residual amount of the pumped medium remains in the inlet chamber after the end of the pumping operation. Furthermore, air often remains in the upper pumping chamber of the pump, which usually has a detrimental effect on the pumping stability (pulsation) and the pump power. The disadvantages of the diaphragm pumps known from DE 102008035592 A1 are that air remains at least in the upper pumping chamber of the diaphragm pump. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to improve known diaphragm pumps with regard to residual evacuation and / or degassing of the pump chamber. [Means for solving the problem]

[0007] This problem is solved by the subject matter of claim 1. Advantageous embodiments are disclosed in the dependent claims and the following description.

[0008] The invention is based on the basic idea that the outlet opening of the outlet valve surrounds the inlet opening of the inlet valve or vice versa. By surrounding the inlet valve opening with the outlet valve opening, air possibly present in the pump chamber can flow from the pump chamber into the outlet chamber through the part of the outlet valve opening arranged above the inlet valve opening and is not trapped in the upper region of the pump chamber, as in some diaphragm pumps of the prior art. By surrounding the inlet valve opening with the outlet valve opening, the pumped fluid located in the lower region of the pump chamber can also flow into the outlet chamber through the region of the outlet opening arranged below the inlet opening, and thus good residual discharge can be achieved. In the diaphragm pump according to the invention, this provides the possibility that the diaphragm pump can be sufficiently evacuated and / or deaerated in a particularly automatic manner. In addition to improved flow distribution, small construction dimensions are made possible, which make it possible to significantly reduce the amount of fluid that can be pumped in the diaphragm pump. Furthermore, it is possible that the outlet chamber and the inlet chamber can be arranged concentrically. Together with the outlet passages, which are arranged in the lower region in the preferred embodiment, the inlet and outlet chambers can now be emptied virtually completely.

[0009] According to the invention, the diaphragm pump has one pumping chamber, advantageously two, particularly preferably three, four or more pumping chambers. These pumping chambers can be changed in volume by an external force, particularly preferably in cycles, in particular periodically. Particularly preferably, at least one wall of the chamber volume is formed by a diaphragm, which is preferably manufactured from an elastic material, for example plastic, rubber, elastomer, silicone or equivalent material, which can also include composite materials, in particular to increase the stability and service life. If the wall formed by the diaphragm is designed so that the chamber provided for forming the pumping chamber can be completely crushed, the pumping chamber can be dimensioned with respect to the maximum available volume of the pumping chamber, so that this maximum volume corresponds exactly to the fluid volume that can be pumped in one pump stroke. However, significantly larger pumping chambers are also possible, which improve, for example, the flow characteristics, the efficiency of the diaphragm pump or the production costs.

[0010] The pump chamber has at least one inlet valve and at least one outlet valve. The inlet valve has an inlet opening that can be closed by an inlet valve body, and the outlet valve has an outlet opening that can be closed by an outlet valve body. Each valve body can be formed, in particular, by an elastic diaphragm, which usually at least partially opens the valve opening that is assigned to the valve body when a corresponding pressure difference is present. The material for the valve body can be, for example, metal, but also in particular plastic, rubber, elastomer, silicone or equivalent materials, including in particular composite materials. When a pressure difference is present in the opposite direction, the valve body closes the valve opening and / or a spring element is provided, which acts on the valve body and preloads the valve body into a closed position in a position outside the closed position in which the valve body closes the valve opening. By diaphragm is meant in particular here a preferably flat plate which often has elastic and / or spring properties, even if only partially, for example by means of flexible edge parts. Furthermore, the valve control device can control the opening and closing of the valve or influence the optimization of the pumping action.

[0011] According to the invention, the outlet opening surrounds the inlet opening or vice versa, which distinguishes the invention from solutions known from the prior art in which the inlet and outlet openings are arranged alongside one another, for example one above the other.

[0012] Particularly preferably, the inlet valve and / or the outlet valve is an umbrella valve, which means a valve whose valve body is formed by an umbrella-shaped member.

[0013] The inlet chamber serves to prepare the fluid. The inlet opening can be formed directly in the wall of the inlet chamber. This allows a compact construction of the diaphragm pump, especially if in a further preferred embodiment the inlet opening opens directly into the pump chamber. However, in a preferred embodiment an inlet passage is provided between the inlet chamber and the pump chamber, connecting the inlet chamber to the pump chamber. This allows the possibility of relatively freely forming the position of the inlet chamber in the interior of the diaphragm pump with respect to the pump chamber.

[0014] The outlet chamber serves to collect and bundle the pumped fluid, in particular for further leading to one central outlet of the diaphragm pump, in particular when several pump chambers and / or outlet valves are provided. The outlet opening may be formed directly in the wall of the outlet chamber. This allows a compact construction of the diaphragm pump, in particular when in further preferred embodiments the outlet opening opens directly into the pump chamber. In preferred embodiments, however, an outlet passage is provided between the outlet chamber and the pump chamber, which connects the outlet chamber to the pump chamber. This allows the possibility of relatively freely forming the position of the outlet chamber in the diaphragm pump with respect to the pump chamber.

[0015] In an alternative aspect of the invention, where the outlet opening surrounds the inlet opening, a preferred embodiment is possible in which the outlet opening is formed by only one ring-shaped opening. "Ring-shaped" means that starting from a central point that the opening surrounds, a portion of the opening is provided in each radial direction. The concept "ring-shaped" is not limited to the description of circular ring-shaped openings. The shape of the free space that forms the opening is determined in particular by the shape of the walls that define the free space. In a circular ring-shaped opening, the opening is defined, for example, by a first circular ring-shaped wall and a second circular ring-shaped wall that is arranged to lie opposite the first circular ring-shaped wall. It can then be recognized that the shape of the free space that forms the opening is defined by an outer wall and an inner wall, viewed in the radial direction from the central point that the opening surrounds. In a preferred embodiment, the outer wall and the inner wall have the same geometric shape. Particularly preferably, the inner wall and the outer wall are formed concentrically with respect to one another. For example, the outer wall and the inner wall are circular, elliptical, rectangular, in particular square or triangular walls. Particularly preferably, at each point in the circumferential direction of the outlet opening, the distance between the inner wall and the outer wall remains equal. This is provided in particular if the outer wall and the inner wall have the same geometric shape. However, also in another possible embodiment, at each point in the circumferential direction of the outlet opening, the distance between the inner wall and the outer wall does not remain equal. In such a case, it can be advantageous to select the distance between the inner wall and the outer wall to be larger in the upper and / or lower region of the outlet opening than in the side regions, so that the fluid flowing through the outlet opening can be provided with a particularly large space, in particular in the upper and / or lower region. This can be obtained in particular in a preferred embodiment by the outer wall and the inner wall not having the same geometric shape or having the same geometric shape but not being formed concentrically with respect to one another.

[0016] In an alternative embodiment of the invention, where the outlet opening surrounds the inlet opening, in a preferred embodiment the outlet opening of the outlet valve is formed by at least two mutually separated outlet opening sections, which surround the inlet opening. The term "outlet opening" is therefore not used within the scope of the invention to refer only to one opening, but instead to a set of several individual openings that are defined from one another. According to a preferred embodiment, the outlet opening is divided into several outlet opening sections. The outlet opening sections are particularly preferably arranged in a ring-like manner around the inlet opening. For example, the outlet opening can be formed by an arc-shaped outlet opening section above the inlet opening and / or by an arc-shaped outlet opening section below the inlet opening, whereas in a particularly preferred embodiment no outlet opening sections are provided to the sides of the inlet opening. The correspondence of the outlet opening section to the outlet valve is achieved in a preferred embodiment in that the outlet opening sections are closed by a common valve body.

[0017] In a preferred embodiment, the outlet opening surrounds the inlet opening, in an alternative aspect of the invention, the inlet opening is formed by a single opening that is not divided into several inlet opening portions, but it is also possible for the inlet opening to be formed by several inlet opening portions, which are arranged spatially inside an envelope circle surrounding the outlet opening portion, for example, instead of a single circular inlet opening, it is also possible to provide a set of circular inlet opening portions arranged next to one another.

[0018] In an alternative aspect of the invention, where the inlet opening surrounds the outlet opening, a preferred embodiment is possible in which the inlet opening is formed by only one ring-shaped opening. "Ring-shaped" means that a portion of the opening is provided in each radial direction starting from the center point that the opening surrounds. The concept "ring-shaped" is not limited to the description of circular ring-shaped openings. The shape of the free space that forms the opening is determined in particular by the shape of the walls that define the free space. In a circular ring-shaped opening, the opening is defined, for example, by a first circular ring-shaped wall and a second circular ring-shaped wall that is arranged to lie opposite the first circular ring-shaped wall. It can then be recognized that the shape of the free space that forms the opening is defined by an outer wall and an inner wall in the radial direction from the center point that the opening surrounds. In a preferred embodiment, the outer wall and the inner wall have the same geometric shape. Particularly preferably, the inner wall and the outer wall are formed concentrically with each other. For example, the outer wall and the inner wall are circular, elliptical, rectangular, in particular square or triangular walls. Particularly preferably, at each point in the circumferential direction of the inlet opening, the distance between the inner wall and the outer wall remains equal. This is provided in particular if the outer wall and the inner wall have the same geometric shape. However, also in another possible embodiment, at each point in the circumferential direction of the inlet opening, the distance between the inner wall and the outer wall does not remain equal. In such a case, it can be advantageous to select the distance between the inner wall and the outer wall to be larger in the upper and / or lower region of the inlet opening than in the side region, so that the fluid flowing through the inlet opening can be provided with a particularly large space, in particular in the upper and / or lower region. This can be obtained in particular in preferred embodiments by the outer wall and the inner wall not having the same geometric shape or having the same geometric shape but not being formed concentrically with respect to one another.

[0019] In an alternative embodiment of the invention, where the inlet opening surrounds the outlet opening, in a preferred embodiment the inlet opening of the inlet valve is formed by at least two mutually separated inlet opening sections, which inlet opening sections surround the outlet opening. The term "inlet opening" is therefore not used within the scope of the invention to refer only to one opening, but instead to a set of several individual openings that are defined from one another. According to a preferred embodiment, the inlet opening is divided into several inlet opening sections. The inlet opening sections are particularly preferably arranged in a ring-like manner around the outlet opening. For example, the inlet opening can be formed by an arc-shaped inlet opening section above the outlet opening and / or by an arc-shaped inlet opening section below the outlet opening, whereas in a particularly preferred embodiment no inlet opening sections are provided on the sides of the outlet opening. The correspondence of the inlet opening sections to the inlet valve is achieved in a preferred embodiment in that the inlet opening sections are closed by a common valve body.

[0020] In a preferred embodiment, the inlet opening surrounds the outlet opening, in an alternative aspect of the invention, the outlet opening is formed by a single opening that is not divided into several outlet opening sections, however, it is also possible for the outlet opening to be formed by several outlet opening sections, these being arranged spatially within an envelope circle surrounding the inlet opening section, for example, instead of a single circular outlet opening, it is also possible to provide a set of circular outlet opening sections arranged next to one another.

[0021] According to another preferred embodiment, the inlet and outlet chambers are formed around a common central axis. The central axis is advantageously formed by the longitudinal axis of the diaphragm pump. In this arrangement, the central axis particularly preferably runs through the inlet chamber and through the outlet chamber. Particularly preferably, a central arrangement of the inlet or outlet chamber is provided. By central arrangement, it is meant that the outlet or inlet chamber has a shape that is rotationally symmetric about a point located on the central axis, or that is point-symmetric about a point located on the central axis, or that is mirror-symmetric with respect to a plane containing the central axis, the central axis running through the area of ​​the outlet chamber and / or the area of ​​the inlet chamber.

[0022] In an alternative embodiment, the inlet chamber is formed around a central axis, which extends through the inlet chamber, whereas the outlet chamber is formed around the central axis, which does not extend through the outlet chamber, the outlet chamber being formed around the central axis, for example in the shape of a ring. This means that, particularly preferably, the outlet chamber and the inlet chamber have a shape which is rotationally symmetric about a point located on the central axis, or which is point symmetric about a point located on the central axis, or which is mirror symmetric with respect to a plane containing the central axis, but the central axis extends only through the area of ​​the inlet chamber, but not through the area of ​​the outlet chamber.

[0023] In an alternative embodiment, the outlet chamber is formed around a central axis, which extends through the outlet chamber, whereas the inlet chamber is formed around the central axis, which does not extend through the inlet chamber, the inlet chamber being formed, for example, in the shape of a ring around the central axis. This means that, particularly preferably, the outlet chamber and the inlet chamber have a shape that is rotationally symmetric about a point located on the central axis, or that is point-symmetric about a point located on the central axis, or that is mirror-symmetric with respect to a plane containing the central axis, but the central axis extends only through the area of ​​the outlet chamber, but not through the area of ​​the inlet chamber.

[0024] According to a preferred embodiment of the invention, the inlet chamber has a centrally arranged inlet passage, from which, in the embodiment with several inlet valves, several supply passages can branch out to the individual inlet valves in a preferred embodiment, with a particularly favorable flow distribution to the inlet valves being achieved via the central inlet passage.

[0025] According to an alternative embodiment, the inlet chamber has a wall in its vertically lower region, which is formed in such a way that it is approximately flush with the lower part of the inlet opening of the at least one inlet valve, in particular the lowest inlet valve or valves merge into the wall of the inlet chamber in the respective lower region of their respective inlet opening, such that the inlet chamber can be completely emptied via the inlet valve and the remaining fluid is pumped from the inlet chamber to the outlet chamber during the pumping action.

[0026] According to a preferred embodiment of the invention, the outlet chamber has a centrally located outlet passage, which in embodiments with multiple outlet valves may in a preferred embodiment have multiple supply passages leading from the individual outlet valves.

[0027] According to an alternative embodiment, the outlet chamber has a wall in its vertically lower region, which is formed in such a way that it is approximately flush with the lower part of the outlet opening of the at least one outlet valve, in particular the lowest outlet valve or valves merge into the wall of the outlet chamber in the respective lower region of their respective outlet opening, such that the outlet chamber can be completely emptied via the outlet valve and the remaining fluid is pumped from the inlet chamber to the outlet chamber during the pumping action.

[0028] In a preferred embodiment, a plurality of pumping chambers are provided, each of which is advantageously provided with at least one inlet valve and / or at least one outlet valve.

[0029] In a preferred embodiment, all outlet valves of the diaphragm pump are configured in the same way as one another, particularly preferably with the same shape of the outlet openings and / or the same shape of the valve body. In a preferred embodiment, all inlet valves of the diaphragm pump are configured in the same way as one another, particularly preferably with the same shape of the inlet openings and / or the same shape of the valve body.

[0030] According to a preferred embodiment of the present invention, one inlet valve is provided for each pump chamber. In a preferred embodiment, an inlet valve plate is provided, on which a number of inlet valves are arranged at a spatial distance from one another. In a particularly preferred embodiment, the diaphragm pump has four pump chambers. In this case, in a preferred embodiment, the inlet valve plate has four inlet valves at a spatial distance from one another.

[0031] According to a preferred embodiment of the present invention, one outlet valve is provided for each pump chamber. In a preferred embodiment, an outlet valve plate is provided, on which outlet valve plate a number of outlet valves are arranged at a spatial distance from one another. In a particularly preferred embodiment, the diaphragm pump has four pump chambers. In this case, in a preferred embodiment, the outlet valve plate has four spatially separated outlet valves.

[0032] In a preferred embodiment, a valve plate is provided having a plurality of inlet valves and a plurality of outlet valves formed therein.

[0033] Particularly preferably, one of the outlet valves is arranged in the vertically lower region of the pump head or of the valve plate in correspondence with one of the outlet channels, which makes it even more convenient to empty the diaphragm pump.

[0034] According to another preferred embodiment of the invention, the number of outlet valves and the number of inlet valves correspond to the number of pump chambers. A number of four pump chambers with correspondingly four outlet valves in the valve plate and correspondingly four inlet valves in the inlet valve plate has proven to be particularly suitable. However, it is also basically possible for each pump chamber to be assigned, for example, two outlet and / or inlet valves or, respectively, more outlet and / or inlet valves.

[0035] According to a preferred embodiment of the invention, a valve plate with one or more pump chambers, one or more outlet valves and one or more inlet valves is arranged between a front plate with an inlet chamber, an intermediate plate with an outlet chamber and a diaphragm support supporting a pump diaphragm. For simple and inexpensive manufacture, the valve plate may be designed approximately flat.

[0036] According to another preferred embodiment, an inlet passage is provided between the inlet chamber and the pump chamber. Particularly preferably, the inlet valve associated with the pump chamber is arranged in the inlet passage, in particular at the beginning or end of the inlet passage. Additionally or alternatively, an outlet passage can be provided between the outlet chamber and the pump chamber. Particularly preferably, the outlet valve associated with the pump chamber is arranged in the outlet passage, in particular at the beginning or end of the outlet passage.

[0037] According to another preferred embodiment, the invention comprises a device for pumping a fluid with a diaphragm pump according to the invention, the pump head having a drive chamber and a drive device, the pump chambers being sealed against the drive chamber by means of a pump diaphragm, in a preferred embodiment, the pump diaphragm can be subjected to a periodic axial pumping movement via a correspondingly arranged pump element.

[0038] Next, the present invention will be described in detail with reference to the drawings showing embodiments of the present invention. [Brief description of the drawings]

[0039] [Figure 1] 1A and 1B are a plan view and a side view of a diaphragm pump (without a drive unit) according to the present invention, taken along line AA in the plan view, showing a pump head. [Diagram 2] FIG. 2 is a front view of the pump head of FIG. 1 together with a valve plate, seen obliquely from the front. [Diagram 3] 2A and 2B are front and rear views showing the front plate of the pump head according to the present invention shown in FIG. 1. [Figure 4] 2A and 2B are front and rear views showing the valve plate of the pump head according to the present invention shown in FIG. 1. [Diagram 5] 2A and 2B are front and rear views showing the intermediate plate of the pump head according to the present invention shown in FIG. 1. [Figure 6] FIG. 2 is a partial cross-sectional view of an apparatus including the diaphragm pump shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] In figure 1 there is shown a pump head 2 of a diaphragm pump 1. The diaphragm pump 1 forms part of the device shown in figure 6.

[0041] The pump head 2 has a front plate 3, an intermediate plate 4, also called the chamber housing, a valve plate 5, and an end plate 6, also called the diaphragm support, which carries a pump diaphragm 7 connected via a pump element to a rotating swash plate, not shown in FIG. 2.

[0042] The front plate 3 is provided with a central inlet section 10 which opens into a central inlet chamber 12 via an inlet passage 11 formed in the front plate 3. The front plate 3 is provided with an outlet section 13 which is connected to a similarly central outlet chamber 14 of the intermediate plate 4 via an outlet passage 15 which is formed partly in the front plate 3 and partly in the intermediate plate 4.

[0043] Between the intermediate plate 4 and the end plate 6, a valve plate 5 is arranged. The valve plate 5 has four pump chambers 18 on its rear side 17 opposite the intermediate plate 4. The pump chambers 18, which open towards the end plate 6, are each closed or defined by a pump diaphragm 7. These pump diaphragms 7 are arranged between the end plate 6 and the valve plate 5. A ring-shaped ridge 19 of the pump diaphragm 7 is arranged in a groove 20 of the valve plate 5, which is arranged around the pump chambers 18.

[0044] The intermediate plate 4 closes the inlet chamber 12 of the front plate 3, but has inlet passages 16 which each lead to an inlet valve 22, which run through the outlet chamber 14 of the intermediate plate 4. The valve plate 5 has four inlet valves 22 which are configured as umbrella valves and which connect the inlet chamber 12 via each passage 16 to a pump chamber 18 which is assigned to each inlet valve 22.

[0045] The valve plate 5 further seals the central outlet chamber 14 of the intermediate plate 4. The valve plate 5 is of approximately flat design and has four outlet valves 24 corresponding to the outlet chambers 14, which are likewise designed as umbrella valves. The outlet openings of the outlet valves 24 are formed by outlet openings 23a of each outlet valve 24, which surround the inlet openings 23b of the inlet valves 22 respectively assigned to the corresponding pump chambers 18, which in turn form the inlet openings of the inlet valves 22. The outlet openings 23a are preferably directly adjacent to the inlet openings 23b, the outlet openings 23a and the inlet openings 23b being separated from each other, in particular by a ridge or a wall.

[0046] The swash plate 9 shown in Figure 6 is connected via ball bearings 25 to a journal 26 of a drive shaft 27. The journal 26 is inclined with respect to the longitudinal axis 28 of the drive shaft 27, which makes it possible to bring about an oscillating movement of the swash plate 8. The connection between the drive shaft and the swash plate 8 is arranged in the region of a drive chamber 29 located in front of the end plate 6.

[0047] The inlet chamber 12 is sealed against the intermediate plate 4 by a sealing element 30, which in the illustrated embodiment is formed as a code ring packing. The outer delimitation of the outlet chamber 14 is sealed by a sealing element 31, which in the illustrated embodiment is likewise formed as a code ring packing. The outlet opening 23a of the valve plate 5 is likewise sealed towards the inlet passage 16 of the intermediate plate 4 by a ridge 34, which is arranged in a groove 33 in the umbrella-shaped valve body of the outlet valve 24.

[0048] By the rotation of the drive shaft 27 about its longitudinal axis 28, the swash plate 8 undergoes a rotary oscillating movement due to the inclination of the journals 26, without rotating together with the drive shaft 27. The oscillating movement of the swash plate 8 causes the pump diaphragm 7 to perform a periodic axial pumping movement, which alternately creates a negative pressure in the pump chamber 18 during the intake stroke by a movement towards the drive chamber 29, and a positive pressure during the discharge stroke by a movement towards the front plate 3.

[0049] Due to the umbrella valve bodies of the inlet valves 22 being respectively arranged downstream, the inlet valves 22 automatically open and the corresponding outlet valves 24 automatically close in the event of negative pressure in the associated pumping chamber 18. In the event of positive pressure in the pumping chamber 18, the associated inlet valves 22 automatically close and the corresponding outlet valves 24 automatically open. As a result, the pump medium is pumped from the pumping chamber 18 through the outlet chamber 14 to the outlet 13.

[0050] Figure 2 shows an oblique front view of the pump head of Figure 1 with the valve plate, from which the order of components such as front plate 3, intermediate plate 4, valve plate 5 and end plate 6 can be seen.

[0051] In Figure 3, the front plate 3 of the pump head according to the invention of Figure 1 is shown in front and rear view. In this figure too, the inlet and outlet passages 11 and 15 as well as the inlet chamber 12 can be clearly seen.

[0052] Figure 4 shows the valve plate 5 of the pump head according to the invention from Figure 1 in front and rear view, in particular the ring-shaped outlet valve 24, the arc-shaped outlet opening 23a and the inlet opening 23b formed as a hole in the pump chamber 18 as well as the inlet valve 22 formed in the shape of a disk.

Claims

1. A diaphragm pump (1) with at least one pumping chamber (18), said pumping chamber (18) being connected to an inlet chamber (11) via an inlet valve (22) and to an outlet chamber (13) via an outlet valve (24), said inlet valve (22) having an inlet opening that can be closed by an inlet valve body, and said outlet valve (24) having an outlet opening that can be closed by an outlet valve body, the outlet opening surrounds the inlet opening, or The inlet opening surrounds the outlet opening. A diaphragm pump comprising:

2. 2. The diaphragm pump according to claim 1, wherein the outlet opening of the outlet valve is formed by at least two outlet openings (23a) spaced apart from one another, the outlet openings (23a) surrounding the inlet opening.

3. 2. The diaphragm pump of claim 1, wherein the inlet opening of the inlet valve is formed by at least two inlet opening portions spaced apart from one another, the inlet opening portions surrounding the outlet opening.

4. 4. The diaphragm pump according to claim 1, wherein the inlet chamber (11) and the outlet chamber (13) are formed around a common central axis.

5. 5. The diaphragm pump according to claim 1, wherein the inlet chamber (11) has a wall in its vertically lower region, the wall being formed in such a way that it is flush with a lower part of the inlet opening of at least one of the inlet valves (22).

6. 6. The diaphragm pump according to claim 1, wherein the outlet chamber (13) has a wall in its vertically lower region, the wall being formed so as to be flush with a lower part of the outlet opening of at least one of the outlet valves (24).

7. 7. The diaphragm pump according to claim 1, further comprising a plurality of pump chambers, each of said pump chambers being provided with at least one inlet valve and at least one outlet valve.

8. 8. The diaphragm pump according to claim 1, wherein the pump chamber (18) is formed as part of a valve plate (5), the valve plate (5) having a plurality of the outlet valves (24).

9. 9. The diaphragm pump according to claim 8, wherein the valve plate (5) has a number of outlet valves (24) corresponding to the number of pump chambers (18).

10. 10. The diaphragm pump according to claim 8 or 9, wherein a valve plate (5) having the pump chamber (18), the inlet valve (22) and the outlet valve (24) is arranged between a part of the diaphragm pump having the inlet chamber (11) and the outlet chamber (13) and a diaphragm support (6) supporting the pump diaphragm (7).

11. 11. The diaphragm pump according to claim 8, wherein an inlet passage (16) is provided between the inlet chamber (11) and the pump chamber (18), and an inlet valve (22) associated with the pump chamber (18) is arranged in the inlet passage (16) or at a start or end of the inlet passage (16).

12. 12. The diaphragm pump according to claim 8, wherein an outflow passage is provided between the outflow chamber and the pump chamber, and an outflow valve corresponding to the pump chamber is arranged in the outflow passage or at a start end or end end of the outflow passage.

13. 12. The diaphragm pump according to claim 8, wherein four pump chambers (18) are provided and at least four outlet valves (24) and at least four inlet valves (22) are arranged on the valve plate (5).

14. 14. A device for pumping a fluid, comprising a diaphragm pump according to claim 1, characterized in that the pump head (2) comprises a drive chamber and a drive device, the pump chamber being sealed against the drive chamber (29) by means of a pump diaphragm (7).

15. 15. The device according to claim 14, wherein the pump diaphragm (7) is capable of a periodic axial pumping movement via an associated pump element (6).

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