The invention relates to a
valve actuator (2), comprising a
magnetic core (6) with an interspace (8) and at least one bifurcating
branch (7), at least one variable
magnetic field generating device (16), at least one permanent
magnetic field generating device (13) and at least one movable magnetic component (12), wherein the bifurcating
branch (7) defines a first region (4) and a second region (5) of said
magnetic core (6). Said movable magnetic component (12) is movably arranged within said interspace (8) of said
magnetic core (6) in such a way that a first gap (19) is formed between a first surface (23) of said movable magnetic component (12) and a first surface (22) of said interspace (8) of said magnetic core (6), a second gap (20) is formed between a second surface (24) of said movable magnetic component (12) and a second surface (25) of said interspace (8) of said magnetic core (6), and a third gap (21) is formed between a third surface (27) of said movable magnetic component (12) and a third surface (26) of said bifurcating
branch (7) of said magnetic core (6). At least one of said variable
magnetic field generating devices (48, 49) is associated with said first region (4) of said magnetic core (6) and at least one of said permanent magnetic field generating devices (13) is associated with said second region (5) of said magnetic core (6). Said
valve actuator (2) is designed and arranged in a way that a
magnetic flux, generated by at least one at least one of said variable magnetic field generating devices (16) is able to exert a force on said at least one movable magnetic component (12) and is able to cancel the
magnetic flux (48, 49), generated by at least one of said permanent magnetic field generating devices (13). At least one
magnetic flux limiting means (7, 12) is provided, whose magnetic flux limit can be reached or exceeded.