Actuator for controlling the flow of a fluid and fluid guiding member with an actuator

An actuator (7) has an adjusting drive mechanism (9) that drives an adjusting body (14) and has moving (13) and non-moving (11) drive parts. The moving drive part and the adjusting body form one unit. Movement in the moving drive part is executed as a linear movement to represent the adjusting body. An independent claim is also included for a guide part for a liquid substance.