| 摘要 |
<p>An actively controlled helicopter rotor blade includes a trailing edge flap (20) actuated by a fast-acting actuator (30). A lightweight, rugged, fast-acting actuator suitable for use as the flap actuator comprises a pair of column actuators (50, 52) composed of a smart material such as piezoelectric, magnetostrictive, shape memory alloy or other material that exhibits a shape change when subjected to an external stimulus. Each of the column actuators (50, 52) is composed of multiple piezoelectric ceramic actuator elements (48) bonded together to form the individual columns. Each of the column actuators (50, 52) engages the base of an actuator tube that, in turn, is urged against the column actuators (50, 52) by a tension member (76). Differential voltage applied to the columns (50, 52) causes a differential elongation of the column actuators (50, 52), which causes the actuator tube (86) to pivot about an axis proximal the tips of the column actuators (50, 56). The movement of the actuator tube (86) is coupled by a linkage to the rotor blade flap. Spherical joints (54, 56, 58, 60, 62, 64, 66, 68) are disposed between the column actuators (50, 52) and the actuator tube to prevent transmission of substantial bending loads to the column actuators (50, 52) and a mid-point support (120) is also provided for each of the column actuators (50, 52) to limit the magnitude of acceleration induced bending loads, which would otherwise lead tensile failure of the ceramic actuator elements (48).</p> |
