Variable-pitch rotor with remote counterweights

A gas turbine engine, comprising:

• a turbomachinery core operable to produce a core gas flow;
• a low pressure turbine positioned downstream of the turbomachinery core;
• an inner shaft coupled to the low pressure turbine;
• a rotor structure coupled to the inner shaft;
• a row of blades carried by the rotor structure, each blade having an airfoil and a trunnion mounted for pivoting movement relative to the rotor structure, about a trunnion, axis which is perpendicular to the longitudinal axis;
• a unison ring interconnecting the blades;
• an actuator connected to the unison ring and the rotor structure, operable to move the unison ring relative to the rotor structure;
• at least one moveable counterweight carried by the rotor structure, remote from the blades;
• and
• an interconnection between the blades and the at least one counterweight, such that movement of the at least one counterweight causes a change in the pitch angle of the blades,
• wherein the rotor structure carries an array of counterweight assemblies comprising at least one pinion gear, and wherein the at least one pinion gear is engaged with a ring gear that is part of the unison ring and with a sun gear that is stationary relative to the rotor structure.