| 摘要 |
An actuating system for a controllable pitch propeller comprises a hydraulic servomotor (4, 5) arranged in the propeller hub (2) and being connected mechanically to the propeller blades (3). Pressure medium is delivered to the servomotor (4, 5), under the control of a control valve (7), from a pressure-medium source (33), which is connected to a stationary pressure-medium chamber (15) which embraces a rotatable shaft (1) connected to the propeller and which is sealed against the outer surface of the shaft and communicates, via a radial pressure-medium channel (19, 20, 21) in said shaft, with an axial pressure-medium channel (10) located in the shaft and extending to the hydraulic servomotor (4, 5). The system further comprises an additional stationary pressure-medium chamber (16) which embraces the shaft and seals against the outer surfaces thereof and which, via an additional radial pressure-medium channel (24, 25, 26) in the shaft communicates with the axial pressure-medium channel (10) in the shaft. The system also comprises an additional pressure-medium source (34), and each of the two pressure-medium sources (33, 34) can be connected alternatively to any one of the two pressure-medium chambers (15, 16), whereby the actuating system can be operated in a substantially unchanged manner irrespective of faults in any of the two pressure-medium sources (33, 34) and irrespective of faults in any of the high-pressure seals (17, 18) of the two pressure-medium chambers (15, 16). |
