Metering system and method for controlling a metering system

A dosing system (1) for dosing a dosing material, which dosing system (1) has a housing (11) comprising a nozzle (70) and a supply channel (62) for dosing material, a discharge element (80) movably mounted in the housing (11), a plunger bearing (83) surrounding the discharge element (80) for guiding the discharge element (80) in an axial direction, and an actuator unit (10) coupled to the discharge element,

• the actuator unit (10) comprising an actuator (12) having a membrane (13) which is pressurized by a pressure medium to move the discharge element (80) in a discharge direction (RA), wherein a gaseous and/or liquid substance is used as the pressure medium, and the pressure medium hits directly on a side surface of the membrane (13) facing away from the discharge element (80), and
• the discharge element (80) being formed separately and being pressed against a side surface (19) of the membrane (13) pointing in the direction of the discharge element (80) by a force acting on the discharge element (80) for coupling to the actuator unit (10),
• wherein the plunger bearing (83) is disposed between the membrane (13) and the nozzle (70), the plunger bearing separating the supply channel (62) from the actuator unit (10);
• and
• wherein the discharge element (80) comprises a plunger head (81) extending radially from one end of the discharge element (80), the plunger head (81) being urged toward the side surface (19) of the membrane (13) by a return spring (84) with one end resting on the plunger bearing (83) and the return spring (84) having an opposite end pressing on an underside of the plunger head (81) to couple the discharge element (80) with the membrane (13), such that the return spring (84) provides a force on the discharge element (80) in the axial direction.