Oscillating displacement machine, in particular oscillating displacement pump

Abstract

Oscillating positive displacement machine with at least one pressure line (14) through which a fluid can flow, into which at least one pulsation damper (11) with a damper chamber is interposed, which damper chamber is divided by at least one separating diaphragm (12) into a fluid-conducting first chamber sub-region (13) and a second chamber sub-region (26) arranged outside the fluid-conducting first chamber sub-region (13), wherein the at least one separating diaphragm (12) is supported by a spring-elastic damping element (15) which is provided in the second chamber sub-region (26) of the damper chamber, characterized in that at least one of the pulsation dampers (11) is divided into diaphragm zones of the separating diaphragm (12) with different levels of compliance.

Description

[0001] The invention relates to an oscillating displacement machine with at least one pressure line through which a fluid can flow, into which at least one pulsation damper with a damper chamber is interposed, which damper chamber is divided by at least one separating diaphragm into a fluid-conducting first chamber sub-region and a second chamber sub-region of the damper chamber arranged outside the fluid-conducting first chamber sub-region, wherein the at least one separating diaphragm is supported by a spring-elastic damping element which is provided in the second chamber sub-region of the damper chamber.The invention also relates to an oscillating positive displacement pump, in particular a diaphragm pump, for conveying liquid or gaseous fluids, which has at least one pulsation damper with a damper chamber on the pressure side, which damper chamber is divided by at least one separating diaphragm into a fluid-conducting first chamber sub-region and a second chamber sub-region of the damper chamber arranged outside the fluid-conducting first chamber sub-region, wherein the at least one separating diaphragm is supported by a spring-elastic damping element which is provided in the second chamber sub-region of the damper chamber.

[0002] EP 1 373 731 B1 discloses a positive displacement pump of the type mentioned above, which is designed as an oscillating positive displacement pump and in particular as a diaphragm pump for liquid or gaseous media. The known positive displacement pump has a pumping chamber defined on one side by a pump head and on the other side by an elastic pumping diaphragm. An inlet valve connected to an inlet nozzle and an outlet valve leading to a pump outlet are connected to the pumping chamber. The known positive displacement pump has a pulsation damper on each of the suction and pressure sides, which are intended to compensate for and minimize pressure surges, vibrations, and other negative effects in the system comprising the known positive displacement pump.The pressure and suction sides of the known positive displacement pump are connected via an overpressure limiting device, wherein the overpressure limiting device as well as the pressure and suction side pulsation dampers are integrated into the pump head in order to reduce pressure peaks on both the suction and pressure sides and to limit a pressure increase on the pressure side to a predeterminable value.

[0003] EP 1 340 016 B1 describes a pulsation damper for an oscillating positive displacement pump, which has an inlet connection, an outlet connection, and a line connecting the inlet and outlet connections, which is connected to several damping chambers within the pulsation damper. These damping chambers are provided within a damper housing, with a line section connected to the inlet connection of the pulsation damper being connected to the oscillating positive displacement pump. These damping chambers are divided by a separating diaphragm into a fluid-conducting first chamber section and a second chamber section arranged outside the fluid-conducting first chamber section. Damping elements made of resilient material are arranged in the second chamber section of the damping chambers.The separating membrane provided in the second chamber section of the damping chambers can have a distance from the damping element, whereby the damper stiffness is graded.

[0004] Pulsation on the suction side and / or on the pressure side of positive displacement machines, which are particularly designed as oscillating positive displacement pumps, for example as diaphragm pumps, can cause cavitation, pressure surges, vibrations and other negative effects in the system where these positive displacement machines are used.

[0005] The objective is to create an oscillating positive displacement machine, and in particular an oscillating positive displacement pump, in which pulsation, at least on the pressure side of this positive displacement machine, can be significantly reduced with the aid of a pulsation damper. The pulsation damper used should be space-saving, cost-effective, and easily adaptable to the requirements of the respective application regarding residual pulsation.

[0006] The solution to this problem according to the invention in the oscillating displacement machine of the type mentioned at the beginning and in particular in the oscillating displacement pump mentioned at the beginning consists in that at least one of the pulsation dampers is divided into membrane zones of the separating membrane with different compliance.

[0007] The positive displacement machine according to the invention, and in particular the positive displacement pump according to the invention, has at least one pressure line through which a gaseous or liquid fluid can flow. Interposed within this pressure line is at least one pulsation damper with a damper chamber. This damper chamber is divided by at least one separating diaphragm into a fluid-conducting first chamber section and a second chamber section located outside the fluid-conducting first chamber section. The at least one separating diaphragm is supported by a spring-elastic damping element provided in the second chamber section of the damper chamber.

[0008] At least one of the pulsation dampers is divided into membrane zones of the separating diaphragm with varying degrees of compliance. In a zone of the separating diaphragm not supported by the damping element, the diaphragm has low stiffness, allowing the pulsation damper to absorb large volumes with small pressure changes and maintain the residual pulsation at the required low level. As soon as a higher counterpressure acts on the separating diaphragm, the separating diaphragm is strongly deflected in the section not supported by the damping element, making the separating diaphragm much stiffer in this section. As a result, the damping element located in the second chamber section and supporting the separating diaphragm also strongly deflects and can also effectively compensate for pressure surges and vibrations.At least one pulsation damper can be optimally adjusted to the required residual pulsation even at different operating pressures and can be manufactured cost-effectively due to its simple and compact design.

[0009] In order to easily divide the separating diaphragm used in the at least one pulsation damper into zones with different degrees of compliance, it is advantageous if the end face or cross-sectional area of ​​the at least one damping element perpendicular to its deflection direction is smaller than the area of ​​the at least one separating diaphragm that is wettable by the fluid in the first chamber section of the damper chamber. In this way, the separating diaphragm is divided into a section that is or can be acted upon by the end face or cross-sectional area of ​​the at least one damping element, and a section of the separating diaphragm that is not supported by the at least one damping element.

[0010] A preferred embodiment according to the invention provides that the at least one separating membrane of the pulsation damper has at least one zone which is supported by the at least one damping element in the second chamber sub-region of the damper chamber.

[0011] In order for the zones of the separating diaphragm of the at least one pulsation damper, which zones have different compliance, to be effective as independently as possible from one another, it is advantageous if the separating diaphragm has an outer annular zone which is not supported by the at least one damping element.

[0012] A particularly simple design and manufacture of the at least one pulsation damper used according to the invention provides that the at least one separating diaphragm of this pulsation damper is clamped in a circumferential clamping zone of the pulsation damper, and that the end face or cross-sectional area of ​​the damping element adjacent to the at least one separating diaphragm is spaced from the clamping zone on all sides. In this way, an outer annular zone is formed that is not supported by the damping element and divides an inner central region supported by the damping element.

[0013] In order to enable a maximum possible deflection of the separating diaphragm in the event of counterpressure at the maximum permissible curvature of the separating diaphragm at its clamping point, in order to promote the greatest possible deflection of the separating diaphragm in the event of volume changes in the damper chamber and in order to optimally utilize the installation space used for the at least one pulsation damper, it is advantageous if the at least one spring-elastic damping element prestresses the at least one separating diaphragm in the direction of the first chamber sub-region of the damper chamber.

[0014] In order to be able to easily adapt the at least one pulsation damper of the positive displacement machine according to the invention, and in particular of the positive displacement pump according to the invention, to the desired pressure in various applications, it is advantageous if the at least one spring-elastic damping element has a non-linear spring characteristic. The spring characteristic of the at least one damping element is best designed such that the at least one damping element is softest at the nominal pressure of the positive displacement machine.

[0015] A particularly advantageous development according to the invention provides that the at least one damping element is made of a volume-compressible material.

[0016] An embodiment according to the invention which is particularly simple in design and manufacture and can be produced cost-effectively provides that the at least one damping element is made of an open- or closed-cell foam.

[0017] In this case, a preferred embodiment is one in which the at least one spring-elastic damping element is made of an elastomer foam and in particular of polyurethane foam.

[0018] In order to protect the at least one pulsation damper against unintentional damage and excessive deflection of the separating diaphragm at high pressures, it is advantageous if at least one separating diaphragm stop is provided in the second chamber sub-region, against which the separating diaphragm rests in the event of excess pressure.

[0019] In the case of an invention designed as an oscillating positive displacement pump and in particular as a diaphragm pump, it is advantageous if the positive displacement pump also has at least one pulsation damper on the suction side.

[0020] In this case, a simple and therefore preferred embodiment according to the invention provides that the at least one suction-side pulsation damper has an oscillating chamber, which oscillating chamber is divided by at least one oscillating diaphragm into a fluid-conducting first chamber sub-region and a second chamber sub-region provided outside the fluid-conducting first chamber sub-region.

[0021] In order to further promote the compact design of the positive displacement pump according to the invention, it is advantageous if the at least one pressure-side and / or suction-side pulsation damper is integrated into the pump head of the positive displacement pump.

[0022] The compact and cost-effective production of the positive displacement pump according to the invention can be further promoted if the oscillating diaphragm of the at least one suction-side pulsation damper and the separating diaphragm of the at least one pressure-side pulsation damper are arranged in approximately one plane - preferably in a separating plane of the at least two-part pump head.

[0023] A preferred design is one in which the vibrating diaphragm and the separating diaphragm are formed integrally in a common diaphragm body clamped in the pump head. Due to the compact design of the positive displacement pump according to the invention, even in the area of ​​its pressure and / or suction-side pulsation dampers, the diaphragms, which are preferably designed as durable elastomer parts, can be made comparatively small, thus achieving significant savings in the area of ​​these expensive elastomer parts.

[0024] A further embodiment of the invention provides that a throttle element is arranged downstream of the pressure-side pulsation damper in the direction of fluid flow, generating a back pressure. This throttles the exchange of fluid in the damper chamber of the at least one pulsation damper and in the pressure line, thus dampening the pressure-side pulsation even more effectively.

[0025] In order to promote good pressure equalization in the second chamber sub-region of the at least one pulsation damper arranged outside the fluid-conducting first chamber sub-region, it is advantageous if the second chamber sub-region of the suction-side pulsation damper and / or the second chamber sub-region of the pressure-side pulsation damper are preferably connected to the atmosphere via at least one ventilation opening in each case.

[0026] Further developments according to the invention will become apparent from the following description of an embodiment according to the invention in conjunction with the claims and the drawing.

[0027] The invention is described in more detail below using a preferred embodiment.

[0028] It shows: Fig. 1 a displacement machine designed here as a positive displacement pump and in particular as a diaphragm pump, which has at least one pulsation damper on the pressure side and preferably also on the suction side, which are integrated here in the pump head of the positive displacement pump, Fig. 2 a pV diagram for the pressure-side pulsation damper of the Fig. 1, wherein the volume change ΔV is shown as a function of the variable pressure p of the conveying fluid in a fluid-carrying first chamber portion of a damper chamber of this pulsation damper, and Fig. 3 the oscillating displacement pump Fig. 1 in a detailed longitudinal section in the area of ​​its pressure-side pulsation damper.

[0029] In the Fig. 1 and Fig. 3 shows an oscillating positive displacement machine, which here is designed as an oscillating positive displacement pump and in particular as a diaphragm pump. The positive displacement machine shown here has a pressure line 14 through which a gaseous or liquid fluid can flow. Interposed into the pressure line 14 is at least one pressure-side pulsation damper 11 with a damper chamber. This damper chamber is divided by at least one separating diaphragm 12 into a fluid-conducting first chamber section 13 connected to the pressure line 14 and a second chamber section 26 arranged outside the fluid-conducting first chamber section 13.The at least one separating diaphragm 12 of the pressure-side pulsation damper 11 is supported by a spring-elastic damping element 15 made of a volume-compressible material, for example, an open- or closed-cell foam, preferably an elastomer foam, and in particular polyurethane foam. The spring-elastic damping element 15 is arranged in the second chamber sub-region 26 of the damper chamber provided in the pressure-side pulsation damper 11 and bears against the separating diaphragm 12 with an end face or cross-sectional area.

[0030] The frontal or cross-sectional area of ​​the at least one damping element 15 at right angles to the direction of its deflection is smaller than the area of ​​the at least one separating membrane 12 that can be wetted by the fluid in the first chamber sub-area 13.

[0031] As can be seen from the Fig. 1 and Fig. As is clear from Figure 3, the at least one separating diaphragm 12 of the pulsation damper 11 is clamped in a circumferential clamping zone in the pulsation damper 11, wherein the end face or cross-sectional area of ​​the damping element 15 adjacent to the at least one separating diaphragm 12 is spaced from the clamping zone on all sides. In this way, the separating diaphragm 12 has an outer annular zone 16 not supported by the at least one damping element 15, which delimits a central zone 27 of the separating diaphragm 12, which zone 27 is supported by the at least one damping element 15. In Fig. 1 it can be seen that the at least one spring-elastic damping element 15 prestresses the at least one separating membrane 12 in the direction of the first chamber portion 13 of the damper chamber.

[0032] The positive displacement machine illustrated here, designed as an oscillating positive displacement pump, also has at least one pulsation damper 28 on the suction side. This at least one suction-side pulsation damper 28 has an oscillating chamber divided by at least one oscillating diaphragm 9 into a fluid-conducting first chamber sub-region 4 interposed in the suction line 10 and a second chamber sub-region 29 provided outside the fluid-conducting first chamber sub-region 4. In order to promote good pressure equalization in the second chamber sub-regions 26, 29 of the pressure-side pulsation damper 11 and / or the suction-side pulsation damper 28, the second chamber sub-region 26 of the pressure-side pulsation damper 11 and / or the second chamber sub-region 29 of the suction-side pulsation damper 28 is each connected to the atmosphere via at least one ventilation opening 30.

[0033] In Fig. 1 shows that the vibrating diaphragm 9 of the at least one suction-side pulsation damper 28 and the separating diaphragm 12 of the at least one pressure-side pulsation damper 11 are arranged in approximately one plane and preferably in a separating plane of the at least two-part pump head 18 of the positive displacement pump. The vibrating diaphragm 9 and the separating diaphragm 12 are integrally formed in a common diaphragm body clamped in the pump head 18.

[0034] The pump head 18 of the positive displacement pump is formed here by an intermediate plate 19, a connection plate 20, and an end plate 21. The working or pumping chamber 6 of the positive displacement pump is formed as a cavity in the intermediate plate 19 of the pump head 18, with this working or pumping chamber 6 being bordered on the one hand by the discharge diaphragm 1 and on the other hand by the intermediate plate 19. The suction valve 5 is arranged in the suction line 10, and the pressure valve 7 is arranged in the pressure line 14 between the intermediate plate 19 and the connection plate 20. The damper chamber of the pressure-side pulsation damper 11 and the oscillation chamber of the suction-side pulsation damper 28 are each formed as cavities between the connection plate 20 and the end plate 21. The diaphragm body forming the separating diaphragm 12 and the oscillating diaphragm 9 is clamped between the connection plate 20 and the end plate 21.The pulsation dampers 11 and 28 are therefore integrated into the pump head 18 of the positive displacement pump.

[0035] The oscillating positive displacement pump, designed here as a diaphragm pump, has the delivery diaphragm 1, which undergoes an oscillating movement by an eccentric drive 2. Adjacent to the pump head 18 of the positive displacement pump is the delivery diaphragm 1, which is moved downwards towards the eccentric drive 2 during the intake stroke and sucks the fluid through the inlet opening 3, the fluid-carrying chamber section 4 of the suction-side pulsation damper 28 and through the suction valve 5 into the working or pumping chamber 6. When the positive displacement pump discharges, the delivery diaphragm 1 is moved upwards in the opposite direction, and the fluid is pumped from the working or pumping chamber 6 through the pressure valve 7 and the first chamber section 13 of the pressure-side pulsation damper 11 towards the outlet opening 8.

[0036] In order to compensate for or dampen the pulsating delivery, the suction-side pulsation damper 28 is arranged on the suction side of the positive displacement pump. This suction-side pulsation damper has the elastic oscillating diaphragm 9 in its oscillating chamber. During the suction stroke, the delivery diaphragm 1 draws on the volume of the oscillating chamber of the suction-side pulsation damper 28, whereby the oscillating diaphragm 9 is deflected downwards in the direction of the eccentric drive 2 and the volume in the fluid-carrying chamber section 4 of the pulsation damper 28 is reduced. During the discharge stroke of the positive displacement pump, the suction valve 5 is closed and the oscillating diaphragm 9 is moved upwards in the opposite direction, whereby the volume of the fluid-carrying first chamber section 4 of the pulsation damper 28 is increased, since the pumped fluid flows in the suction line 10, which is designed, for example, as a hose, due to inertia.

[0037] In order to compensate for or dampen the pulsating delivery on the pressure side of the positive displacement pump, the positive displacement pump also has the pressure-side pulsation damper 11. During the discharge stroke, the elastic separating diaphragm 12 of the pulsation damper 11 is moved upwards in the direction away from the eccentric drive 2. During the suction stroke, the separating diaphragm 12, in contrast, moves downwards again and releases volume from the fluid-carrying first chamber section 13 of the pulsation damper 11 via the outlet opening 8 into the pressure line 14, which is preferably designed as a hose. The suction-side pulsation damper 28 and the pressure-side pulsation damper 11 of the positive displacement pump significantly reduce pressure peaks in the suction and pressure lines 10, 14, which are at least partially designed as hoses, and in the working or pumping chamber 6.

[0038] In order for the pressure-side pulsation damper 11 to function as effectively as possible and to keep the residual pressure pulsation at the outlet of the pressure line 14 as small as possible, the volume change ΔV of the fluid-carrying first chamber section 13 in the pulsation damper 11 must be large with a pressure change Δp. This corresponds to a large gradient of the pV diagram according to Fig. 2, which characterizes the pulsation damper 11. Since the positive displacement pump operates with up to several bar of backpressure, attention must be paid to the maximum permissible deformation of its pressure-side pulsation-damping components 12, 15.

[0039] From the Fig. From the curve shown in Figure 2, it can be seen that a linear characteristic curve (dashed line) has a smaller gradient at low backpressure, resulting in higher residual pulsation. The damping characteristics of the pulsation dampers 11, 28, and in particular of the pressure-side pulsation damper 11, can be designed to meet the requirements as best as possible in a compact design. This compact design of the positive displacement pump, including the area of ​​its pulsation dampers 11, 28, is also advantageous because the separating diaphragm 12 and vibrating diaphragm 9, which are made of durable materials, have a high material cost.

[0040] The separating diaphragm 12 of the pressure-side pulsation damper 11 is divided into zones. The outer annular zone 16, not supported by the damping element 15, has a low rigidity, allowing a large volume change in this area of ​​the separating diaphragm 12 to be compensated for with a small pressure change, thus keeping the residual pulsation at the required low level.

[0041] In the Fig. The detailed longitudinal section shown in Figure 3 shows the pressure-side pulsation damper 11 at higher back pressure. As can be seen from Fig. 3, the separating diaphragm 12 is strongly deflected in the outer annular zone 16 not supported by the damping element 15, whereby the separating diaphragm 12 becomes much stiffer in this area. As a result, the damping element 15 also compresses significantly and is now the primary flexible element. The stiffness of the damping element 15, which is preferably made of open- or closed-cell foam and in particular of polyurethane, decreases with increasing deflection and increases again with further increasing deflection. The hardness of the material used for the damping element 15 and the surface area ratio of the non-clamped area of ​​the separating diaphragm 12 compared to the damping element 15 can be designed such that the deflection of the damping element 15 is in the range of minimum stiffness and the pressure-side pulsation damper 11 is at its most effective.

[0042] From a comparison of the Fig. 1 and Fig. 3 it becomes clear that the damping element 15 is held only in a comparatively short front end region facing away from the separating diaphragm 12 in a complementarily formed recess 23 of the pump head 18 and that outside this blind hole 23 an annular gap is provided between the damping element 15 and the pump head 18.In order for the damping element 15 to be able to expand laterally unhindered over as large a portion of its longitudinal extent as possible when subjected to pressure, the damping element is held in the complementarily formed recess of the pulsation damper with a first end region facing away from the separating diaphragm 12, and the second portion of the damping element protruding beyond the recess is spaced circumferentially from the inner wall of the damper chamber, wherein the first end region of the damping element 15 protruding into the recess 23 is less than half, preferably less than 1 / 5, and in particular - as here - less than 1 / 8 of the longitudinal extent of the damping element 15 compared to its second portion protruding beyond the recess 23. In this way, the damping element 15 can deflect more at a certain pressure than if the damping element 15 were enclosed and unable to deflect radially.

[0043] In the Fig. 1, the separating diaphragm 12 is pre-tensioned by the damping element 15, so that the separating diaphragm 12 is pressed into the fluid-carrying first chamber section 13 of the pulsation damper 11. In this way, with a maximum permissible curvature of the separating diaphragm 12 in its clamping zone, a maximum possible deflection of the separating diaphragm 12 results between the illustration in Fig. 1 at low counterpressure and the representation in Fig. 3 at maximum backpressure. With the advantageously large deflection and volume change in chamber section 13 of the damper chamber per pressure change, the residual pulsation is also reduced. This ensures optimal use of the installation space.

[0044] To protect the separating diaphragm 12 in the event of excessive overpressure, an area of ​​the pump head 18, formed here as an annular zone, is designed as a separating diaphragm stop 17. The separating diaphragm 12 can rest against this stop 17 in the event of excessive pressure and is thus prevented from further deformation, thus preventing excessive loading of the separating diaphragm 12.

[0045] In Fig. 1 shows that a throttle element 22 can be arranged at the pump outlet 8 of the pressure-side damper volume, generating a specific back pressure. This throttles the exchange of pumped medium between the pulsation damper 11 and the downstream sections of the pressure line 14 in the pumping direction, and the pulsation is dampened even more effectively.

[0046] The positive displacement pump shown here is characterized by its compact design, including the integrated pulsation dampers 11, 28, and its cost-effective construction. In particular, the pressure-side pulsation damper 11 can be optimally adjusted to the required residual pulsation at various operating pressures. Since the vibrating diaphragm 4 of the suction-side pulsation damper 28 and the separating diaphragm 12 of the pressure-side pulsation damper 11 are integrally formed in a common elastic diaphragm body, which can be clamped or clamped between the connection plate 20 and the end plate 21 of the pump head 18, the positive displacement pump shown here has a very simple design, comprising only a few parts and enabling easy assembly.

[0047] Since the positive displacement pump shown here significantly reduces pulsation at the pump inlet and outlet, cavitation, pressure surges, vibrations, and other negative effects are avoided in systems where the positive displacement pump shown here is used. The positive displacement pump is space-saving and cost-effective and is adapted to the application requirements regarding residual pulsation. Since the pulsation dampers 11, 28 of the positive displacement pump feature durable oscillating or isolating diaphragms 9, 12, the positive displacement pump can be operated hermetically sealed, chemically resistant, position-independent, and long-lasting, even in the area of ​​the pulsation dampers. This means that the advantages of diaphragm pumps are also retained in the area of ​​the pulsation dampers 11, 28. List of reference symbols 1 conveyor membrane 2 eccentric drive 3 Inlet opening 4 Fluid-carrying chamber section in the oscillation chamber of the suction-side pulsation damper 28 5 Suction valve 6 Working or pumping room 7 Pressure valve 8 Pump outlet 9 Vibration diaphragm of the suction-side pulsation damper 28 10 Suction line 11 pressure-side pulsation damper 12 Separating diaphragm of the pressure-side pulsation damper 11 13 fluid-carrying first chamber section in the damper chamber of the pressure-side pulsation damper 11 14 Pressure line 15 Damping element 16 outer ring zone of the separating diaphragm 12 not supported by the damping element 15 17 stop 18 Pump head 19 Intermediate plate 20 connection plate 21 End plate 22 Throttle organ 23 Formation or blind hole 24 Annular gap 26 non-fluid-carrying chamber section of the damper chamber of the pressure-side pulsation damper 11 27 central zone of the separation membrane 12 28 suction-side pulsation damper 29 non-fluid-carrying second chamber section of the suction-side pulsation damper 28 30 Ventilation opening QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 1 373 731 B1

[0002] EP 1 340 016 B1

[0003]

Claims

[1] Oscillating displacement machine with at least one pressure line (14) through which a fluid can flow, into which at least one pulsation damper (11) with a damper chamber is interposed, which damper chamber is divided by at least one separating diaphragm (12) into a fluid-conducting first chamber sub-region (13) and a second chamber sub-region (26) arranged outside the fluid-conducting first chamber sub-region (13), wherein the at least one separating diaphragm (12) is supported by a spring-elastic damping element (15) which is provided in the second chamber sub-region (26) of the damper chamber, characterized by that at least one of the pulsation dampers (11) is divided into membrane zones of the separating membrane (12) with different compliance. [2] Oscillating positive displacement pump, in particular diaphragm pump, for conveying liquid or gaseous fluids, which has at least one pulsation damper (11) with a damper chamber on the pressure side, which damper chamber is divided by at least one separating diaphragm (12) into a fluid-conducting first chamber sub-region (13) and a second chamber sub-region (26) arranged outside the fluid-conducting first chamber sub-region (13), wherein the at least one separating diaphragm (12) is supported by a spring-elastic damping element (15) which is provided (15) in the second chamber sub-region (26) of the damper chamber, characterized by that at least one of the pulsation dampers (11) is divided into membrane zones (16, 27) of the separating membrane (12) with different compliance. [3] Positive displacement machine or positive displacement pump according to claim 1 or 2, characterized bythat the end or cross-sectional area of ​​the at least one damping element (15) at right angles to the direction of its deflection is smaller than the area of ​​the at least one separating membrane (12) that can be wetted by the fluid in the first chamber sub-region (13) of the damper chamber. [4] Positive displacement machine or positive displacement pump according to claims 1 to 3, characterized by that the at least one separating membrane (12) of the pulsation damper (11) has at least one zone (27) which is supported in the second chamber sub-region (26) of the damper chamber by the at least one damping element (15). [5] Positive displacement machine or positive displacement pump according to one of claims 1 to 4, characterized by that the separating membrane (12) has an outer annular zone (16) which is not supported by the at least one damping element (15). [6] Positive displacement machine or positive displacement pump according to one of claims 1 to 5, characterized bythat the at least one separating membrane (12) is clamped in a circumferential clamping zone of the pulsation damper (11), and that the end face or cross-sectional area of ​​the damping element (15) lying against the at least one separating membrane (12) is spaced apart from the clamping zone on all sides. [7] Positive displacement machine or positive displacement pump according to one of claims 1 to 6, characterized by that the at least one spring-elastic damping element (15) prestresses the at least one separating membrane (12) in the direction of the first chamber sub-region (13) of the damper chamber. [8] Positive displacement machine or positive displacement pump according to one of claims 1 to 7, characterized by that the at least one spring-elastic damping element (15) has a non-linear spring characteristic. [9] Positive displacement machine or positive displacement pump according to one of claims 1 to 8, characterized by that the at least one damping element (15) is made of a volume-compressible material. [10] Positive displacement machine or positive displacement pump according to one of claims 1 to 9, characterized by that the at least one damping element (15) is made of an open- or closed-cell foam. [11] Positive displacement machine or positive displacement pump according to one of claims 1 to 10, characterized by that the at least one spring-elastic damping element (15) is made of an elastomer foam, in particular of polyurethane foam. [12] Positive displacement machine or positive displacement pump according to one of claims 1 to 11, characterized by that in the second chamber section (26) of the pulsation damper (11) a separating membrane stop (17) is provided, against which the separating membrane (12) rests in the event of excess pressure. [13] Positive displacement pump according to one of claims 2 to 12, characterized by that the positive displacement pump has at least one pulsation damper (28) on the suction side. [14] Positive displacement pump according to claim 13, characterized byin that the at least one suction-side pulsation damper (28) has an oscillating chamber, which oscillating chamber is divided by at least one oscillating diaphragm (9) into a fluid-conducting first chamber sub-region (4) and a second chamber sub-region (29) arranged outside the fluid-conducting first chamber sub-region (4). [15] Positive displacement pump according to claim 13 or 14, characterized by that the at least one suction-side pulsation damper (28) and / or the at least one pressure-side pulsation damper (11) is integrated into the pump head (18) of the positive displacement pump. [16] Positive displacement pump according to one of claims 13 to 15, characterized by that the oscillating diaphragm (9) of the at least one suction-side pulsation damper (28) and the separating diaphragm (12) of the at least one pressure-side pulsation damper (11) are arranged in approximately one plane - preferably in a separating plane of the at least two-part pump head (18). [17] Positive displacement pump according to one of claims 13 to 16, characterized by that the vibrating membrane (9) and the separating membrane (12) are formed integrally in a common membrane body clamped in the pump head (18). [18] Positive displacement pump according to one of claims 2 to 17, characterized by that a throttle element (22) which generates a dynamic pressure is arranged downstream of the pressure-side pulsation damper (11) in the flow direction of the fluid. [19] Positive displacement machine or positive displacement pump according to one of claims 1 to 18, characterized by that the second chamber sub-region (29) of the suction-side pulsation damper (28) and / or the second chamber sub-region (26) of the pressure-side pulsation damper (11) is preferably connected to the atmosphere via at least one ventilation opening (30) in each case. [20] Positive displacement machine or positive displacement pump according to one of claims 1 to 19, characterized bythat the damping element (15) is held with a first end region facing away from the separating membrane (12) in a complementarily designed recess (23) of the pulsation damper (11), that the second partial region of the damping element (15) projecting beyond the recess (23) is spaced circumferentially from the inner wall of the damper chamber and that the first end region of the damping element (15) is less than half, preferably less than 1 / 5 and in particular less than 1 / 8 of the longitudinal extent of the damping element (15) compared to its second partial region.

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