LOWER ATTACHMENT FOR TRIMMABLE HORIZONTAL STABILISER ACTUATOR

摘要

A lower attachment system for a trimmable horizontal stabiliser actuator (THSA) includes a screwshaft forming a part of or coupled to a main screw of the actuator, the screwshaft having an axial direction and a primary ballnut disposed on the screwshaft and forming a part of a primary load path of the lower attachment system. The THSA also includes a lower secondary nut and an upper secondary nut as well as a secondary connection arranged for axial and rotational movement and coupled to each of the lower secondary nut and the upper secondary nut. The secondary connection is arranged to be loaded when the secondary load path is loaded and the secondary load path also includes the upper and lower secondary nuts.

主权项

1. A lower attachment system for a trimmable horizontal stabiliser actuator comprising:
a screwshaft forming a part of or coupled to a main screw of the actuator, the screwshaft having an axial direction; a primary ballnut disposed on the screwshaft and forming a part of a primary load path of the lower attachment system; a lower secondary nut disposed on the screwshaft axially adjacent the primary ballnut; an upper secondary nut disposed on the screwshaft adjacent the lower secondary nut and on the opposite side thereof to the primary ballnut; and a secondary connection arranged for axial and rotational movement and coupled to each of the lower secondary nut and the upper secondary nut; wherein the secondary connection is arranged to be loaded when the secondary load path is loaded and the secondary load path also includes the upper and lower secondary nuts; and wherein the couplings between the secondary connection and the upper and lower secondary nuts are arranged such that during normal use, when the primary ballnut transmits the loading of the actuator along the primary load path, then there is no relative rotational movement of the secondary connection, the upper secondary nut and the lower secondary nut, and such that when the secondary connection is subject to an axial load resulting from load being transferred to the secondary load path, the upper secondary nut and lower secondary nut are compelled to rotate relative to one another thereby locking the threads of the secondary nuts with the screwshaft.