Actuator assembly

Abstract

An actuator assembly (1) comprising: a support structure (2); a movable part (10); a helical bearing arrangement (20) arranged to guide helical movement of the movable part relative to the support structure around a helical axis (H); a loading arrangement (50) arranged between the support structure and the movable part for loading the helical bearing arrangement; and at least one pair of actuator components (40) arranged, on actuation, to drive rotation of the movable part in opposite senses around the helical axis which the helical bearing arrangement converts into said helical movement; wherein the at least one pair of actuator components is arranged to apply an unloading torque about an axis perpendicular to the helical axis so as to reduce loading of the helical bearing arrangement.

Dependencies are inferred from the claim text.