US Patent 10174763 Variable pitch fan for gas turbine engine

A variable pitch fan assembly for an aero gas turbine engine that includes a row of fixed pitch blades in a core stream flow and a row of variable pitch blades in a bypass stream flow, and where a sync ring with a number of hydraulic actuators within a flow splitter of the fan stage is used to vary a pitch of each of the bypass stream flow blades. Hydraulic fluid lines pass through the shaft and through the fixed pitch fan blades into the hydraulic actuators to move the sync ring and vary a pitch of the variable pitch bypass flow fan blades.