Multiple stage, multiple extend, speed reducing ball screw linear actuator and method of constructing and operating the actuator

摘要

A multiple extend ball screw and nut linear actuator incorporates a revolvable axially restrained ball screw with a ball nut thereon. A constant speed reversible drive revolves the screw to move the ball nut forwardly and rearwardly. External helical threads of the same hand as the ball nut threads are provided externally on the ball nut but have a substantially reduced lead. A second rotatably restrained nut having threads matching the external threads on the ball nut mounts on the ball nut and connects to the system to be actuated.