JAM RESISTANT BALL SCREW ACTUATOR

摘要

An actuator (10) is disclosed for movement between a retracted position and an extended position. The actuator (10) can be used to pivot a pylon (14) in a tilt rotor aircraft relative to the aircraft wing (12) between a helicopter mode and an aircraft mode. The actuator (10) is provided with an inner ball screw drive unit (20) and an outer ball screw drive unit (22) which provides for limited motion should one of the drive units jam. Further, the actuator (10) can be operated from either end of the actuator. Each ball screw (28, 52) in the actuator is associated with a tube (30, 54), preferably of carbon fiber composite, which forms a secondary load path if the screw fails.