摘要 |
The upstream ends of the flaps of a variable area nozzle are pivotally connected to an axially translatable unison ring. Apparatus is associated with the flaps to cause the flaps to rotate as the unison ring is translated to vary the area of the nozzle. The unison ring includes a balance surface fixed relative thereto which is subject to a net pressure load in the downstream direction thereby reducing the force which an actuator must exert to move the unison ring or to hold the unison ring in fixed position. Preferably the balance surface is an annular surface which extends radially inwardly and has a radially inner edge to which the upstream ends of the flaps are pivotally attached. |