Movable actuator device for controlling the pitch of fan blades of a turboprop

A device for controlling pitch of fan blades of a turboprop including at least one set of adjustable-pitch fan blades, the set being secured to rotate with a rotary ring centered on a longitudinal axis and mechanically connected to a turbine rotor, each blade of the set being coupled for pitch adjustment to a synchronization ring centered on the longitudinal axis, the device comprising:

• an actuator centered on the longitudinal axis, secured to rotate with the turbine rotor and mechanically connected to the synchronization ring by a plurality of connection arms each comprising an axial link connected to the actuator rod, a radial link connected to the synchronization ring, and at least one bellcrank connecting the axial link to the radial link such that actuating the actuator causes the synchronization ring to move in turning about the longitudinal axis.