ACTUATOR FOR AN ELECTRIC EXPANSION VALVE FOR A REFRIGERATION OR AIR-CONDITIONING CIRCUIT OF A MOTOR VEHICLE, AND ELECTRIC EXPANSION VALVE HAVING SUCH AN ACTUATOR

Actuators (12) for electric expansion valves (10) for refrigeration or air-conditioning circuits in motor vehicles, having a brushless DC motor (14) with a stator (16) and a rotor (18), a containment can (24) with a base (26) and a radially delimiting lateral surface (28) which is arranged between the radially externally situated stator (16) and the radially internally arranged rotor (18), a spindle nut (62) which is coupled to the rotor (18) for conjoint rotation, and a spindle rod (64) which is axially movable and secured against rotation, are known. Also known are expansion valves (10) having such an actuator (12), and a control element (66) which is formed on the end of the spindle rod (64) situated opposite the permanent magnet (86) and which interacts with a valve seat (68) which is formed on a housing (34) of the expansion valve (10). In order to improve the position detection accuracy, it is proposed according to the invention that, on the end of the spindle rod (64) pointing toward the base (26) of the containment can (24), there is arranged a permanent magnet (86) which interacts with a stroke sensor (82) which is arranged centrally on that side of the base (26) of the containment can (24) which is situated opposite the spindle rod (64).