摘要 |
PURPOSE:To improve operation performance and engine efficiency by turning a propeller at constant pitch in high power range and varying the pitch at the constant rotational frequency of the propeller in low power range. CONSTITUTION:A propulsion device 1 consists of an engine 2, a variable propeller 4 coupling with it through a shaft system 3, and a variable node device 5 which sends a variable node signal theta, and a controller 6 controls the rotational frequency of the engine 2 and the pitch of a varable pitch propeller. In high power range, a pitch setter 15 holds a high constant pitch value, and a rotational-frequency setter 10 outputs a set signal Ns to vary the rotational frequency of the engine by an engine output command signal F outputted through a rotational-frequency variation rate setter 11, a governor input operator 12, a governor 13, and an output limiter 14, thus varying a speed. In low power range, on the other hand, the rotational-frequency setter 10 holds a low constant value, and the pitch setter 15 outputs a set signal thetas to vary the pitch of the propeller 4 through a setter 16 for a pitch variation rate and the variable node device 5, thus performing variation in speed and forward and backward movements. |