BLADE PITCH CONTROL

• Main Authors: Marger, Thibaut, Bouloc, Romain
• Format: Patent
• Language: English; French; German
• Published: 24.08.2022
• Subjects: AEROPLANES; AIRCRAFT; AVIATION; BLASTING; COSMONAUTICS; ENGINE PLANTS IN GENERAL; HEATING; HELICOPTERS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; PERFORMING OPERATIONS; STEAM ENGINES; TRANSPORTING; WEAPONS

A blade pitch control assembly comprising a pitch control actuator (1) having a coarse actuator chamber (11) having a coarse chamber area and a fine actuator chamber (12) having a fine chamber area, the coarse chamber area being biased to a feather position, and a primary pitch control valve (2) configured to control the flow of pressurised fluid to the coarse actuator chamber (11) and the fine actuator chamber (12), respectively via a coarse fluid line (37') and a fine fluid line (38'); the assembly further comprising a hydraulic protection system located between the actuator (1) and the primary pitch control valve (2), configured to bypass the primary pitch actuator ( in response to a trigger; wherein the hydraulic protection system comprises a hydraulic protection system valve (3) located between the coarse fluid line (37') and the fine fluid line (38'), wherein activation of the hydraulic protection system valve (3) fluidly connects the coarse fluid line (37') and the fine fluid line (38') so as to balance fluid pressure between the coarse chamber (11) and the fine chamber (12).