时间:2011-03-11 23:13来源:蓝天飞行翻译 作者:admin 点击:次
flying wing. A type of heavier-than-air aircraft that has no fuselage or separate tail surfaces. The engines and useful load are carried inside the wing, and movable control surfaces on the trailing edge provide both pitch and roll control. flyweights (speed sensors). Speed sensors used in many types of governors and speed-control devices. A typical flyweight is an L-shaped arm, pivoted at the center, and mounted on a spinning plate. There are usually two or three flyweights mounted on the same plate. A control rod is held against the flyweight by a control, or speeder, spring. When the plate is not spinning, the speeder spring holds the control rod down, and the toes of the flyweights rest against the plate. This is called the underspeed condition. When the plate is spinning and the pressure of the speeder spring is weak, centrifugal force causes the flyweights to sling out and lift the control rod. This is called the overspeed condition. When the centrifugal force on the flyweights exactly balances the compressive force of the speeder spring, the flyweights stand straight up, and the control rod is in a middle position. This is called the onspeed condition. flywheel. A heavy wheel used to smooth the pulsations in a drive system. A reciprocating engine delivers its power in a series of pushes as each cylinder, in turn, goes through its power stroke. A heavy flywheel stores kinetic energy from each power stroke and gives it back by keeping the engine turning between power strokes. An airplane engine does not need a flywheel, because the propeller serves the same purpose. |