Diaphragm pump with shaped diaphragm having radially and circumferentially extending ribs

A diaphragm pump (1) comprising a shaped diaphragm (2) of elastic material located in a pump case having a pumping chamber with a wall adjacent to the shaped diaphragm (2), the shaped diaphragm (2) including a central zone (3) which is thickened in a direction of stroke (4) of the diaphragm pump (1), a flexible annular zone (5) surrounding the central zone (3), an external clamping edge (6) connected to the flexible annular zone (5), the external clamping edge (6) being attached to the pump case, an upper surface (15) of the shaped diaphragm facing the adjacent wall, and an underside (17) of the shaped diaphragm facing away from the pumping chamber, a connecting rod (11) acting on the central zone of the shaped diaphragm (2) to displace the diaphragm from a top dead-center position to a bottom dead-center position and vice versa, wherein the central zone (3) of the upper surface (15) of the diaphragm facing the pumping chamber (16) and the adjacent wall (14) of the pumping chamber are geometrically adapted to each other, and at least the annular zone (5) of the underside (17) of the diaphragm facing away from the pumping chamber (16) is provided with radial ribs (18) for stabilization, and at least one stabilizing rib (19) running substantially in a circumferential direction is arranged at the underside (17) of the annular zone (5) between adjacent radial ribs (18).