Actuator of an electrical regulating equipment

Electric equipment for regulating a flow of fluid in a conduit, of the regulating valve type, the equipment comprising:

• an actuator equipped with a regulating member, of the butterfly valve type, the position of which within the conduit determines at least one parameter of the flow of fluid flowing from upstream to downstream of the regulating member, said actuator comprising a housing and an electric motor provided with a drive shaft adapted to be rotated when the motor is supplied with electric power;
• a concentric, reversible, planetary reducing gear housed in said housing of the actuator and mechanically connected to said drive shaft and comprising a first reducing stage comprising a sun gear fixedly attached to a toothed wheel rotationally driven by said drive shaft and meshing with a second reducing stage comprising at least one planet gear with superposed outer double toothing, respectively called top toothing and bottom toothing, said top toothing of each planet gear meshing with said sun gear and engaged with a fixed ring gear with inner toothing fixedly attached to said housing and said bottom toothing of each planet gear being engaged with a mobile ring gear with inner toothing fixedly attached to an output shaft, mechanically connected to said regulating member;
• and,
• a concentric torsion spring arranged around said mobile ring gear, mechanically connected to the housing and to the mobile ring gear, and configured to be able to spontaneously cause the movement of said mobile ring gear and of said output shaft into a predetermined position in the event of a loss of electric power supply of said electric motor.