Patent ID: 9663218
Date: 2017-05-30
CPC Classifications: B64C,B64D,F01D,F02K,F05D,Y02T

Claim:
1. A hydraulic system for controlling orientation of fan blades in a turbine engine comprising: at least one set of adjustable pitch fan blades actuated by actuators that are connected to a hydraulic pump; and a small pitch protection valve controlled by an associated solenoid valve for passing, when the orientation of the blades is substantially perpendicular to the axis of the turbine engine, from a first operating zone in which a speed of pitch variation of the blades is low to a second operating zone in which the speed of pitch variation is higher; wherein the operating pressure of the hydraulic pump is controlled by the solenoid valve controlling the small pitch protection valve to define two outlet levels corresponding to the two operating zones.