Diaphragm pump

1. A diaphragm pump ( 1 ) comprising at least two pump heads ( 3 ) arranged around a central eccentric pump drive ( 2 ), wherein

the at least two pump heads are ( 4 ) drivingly connected by connecting rods ( 5 ) to the eccentric pump drive ( 2 ),

the eccentric pump drive ( 2 ) comprises a connecting rod ring ( 6 ), that is connected to ends ( 9 ) of the connecting rods via respective elastic intermediate elements ( 10 ),

the connecting rod ring at an exterior thereof includes recesses, each open at the edges thereof, for at least partially accepting the ends of the connecting rods connected to the elastic intermediate elements, and

the elastic intermediate element in each case forms an intermediate layer between recess walls of the recesses and the connecting rod ends.

2. A diaphragm pump according to claim 1 , wherein a deflection of the elastic intermediate elements ( 10 ) is smaller in comparison to an elastic deflection transverse to an axial direction of the connecting rods ( 5 ), and in an approximately radial direction of the connecting rods ( 5 ) a lateral deflection occurring is sized according to a pendulum motion of the connecting rods ( 5 ).

3. A diaphragm pump according to claim 1 , wherein the intermediate elements ( 10 ) are connected to the respective ends ( 9 ) of the connecting rods and the connecting rod ring ( 6 ) by vulcanization.

4. A diaphragm pump according to claim 1 , wherein the ends ( 9 ) of the connecting rods comprise a cross-sectional expansion, which is at least partially located inside the respective one of the elastic intermediate elements ( 10 ).

5. A diaphragm pump according to claim 4 , wherein the cross-sectional expansion of the ends ( 9 ) of the connecting rods is formed by an approximately spherical or spherical-disk shaped formation or by a cylindrical cross pin.

6. A diaphragm pump according to claim 1 , wherein an axial distance of the ends ( 9 ) of the connecting rods from an interior wall of the recess ( 11 , 11 a ) is small and a radial distance of the ends ( 9 ) of the connecting rods from the interior wall of the recess is large.

7. A diaphragm pump according to claim 1 , wherein the recesses ( 11 , 11 a ) in the connecting rod ring ( 6 ) for spherical or spherical-disk shaped formations at the ends ( 9 ) of the connecting rods have a form deviating in cross-section from a partially circular shape.

8. A diaphragm pump according to claim 1 , wherein the recesses ( 11 , 11 a ) in the connecting rod ring ( 6 ) are embodied approximately semi-spherical or semi-spherical disk shaped, or cylindrical and the formations at the ends ( 9 ) of the connecting rods are embodied approximately spherical or spherical-disk shaped or cylindrical and the recesses ( 11 , 11 a ) and the formations are sized such that the formations fit into the recess ( 11 , 11 a ) in their entirety.

9. A diaphragm pump according to claim 1 , wherein a ratio of an axial distance (a) of the end ( 9 ) of the connecting rod to a radial distance (b) of the end ( 9 ) of the connecting rod, each from an interior wall of the recess ( 11 , 11 a ), ranges from approximately 1:1 to approximately 1:5.

10. A diaphragm pump according to claim 1 , wherein the end ( 9 ) of the connecting rod facing the drive comprises a connecting part to connect to the intermediate element ( 10 ) and the connecting part has a coupling point for connecting to the connecting rod ( 5 ).

11. A diaphragm pump according to claim 1 , wherein suction lines ( 17 ), on the one side, and pressure lines ( 18 ) of the pump heads ( 3 ), on the other side, are connected to each other for liquids to flow.

12. A diaphragm pump according to claim 1 , wherein the pump comprises four pump heads ( 3 ) arranged around the central eccentric pump drive ( 2 ).

13. A diaphragm pump according to claim 1 , wherein the connecting rods ( 5 ) of all pump heads ( 3 ) are arranged in a common plane.

14. A diaphragm pump according to claim 1 , wherein the elastic intermediate elements ( 10 ) are formed from a vulcanized elastomer, a thermoplastic elastomer or a pourable elastomer.