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A control for a hydraulic propeller pitch actuator includes a low power pilot valve responsive to digital electronic input signals to control movement of a hydraulic servomotor driving a higher power servovalve. Negative feedback motion is delivered from the servomotor to both the pilot valve and th

A control for a hydraulic propeller pitch actuator includes a low power pilot valve responsive to digital electronic input signals to control movement of a hydraulic servomotor driving a higher power servovalve. Negative feedback motion is delivered from the servomotor to both the pilot valve and the servovalve.

대표청구항 ▼

A variable pitch propeller assembly comprising: a hub carrying a plurality of radially extending propeller blades, said propeller blades mounted to rotate within said hub to adjust blade pitch; a propeller pitch piston positioned to translate within said hub and connected to said propeller blades su

A variable pitch propeller assembly comprising: a hub carrying a plurality of radially extending propeller blades, said propeller blades mounted to rotate within said hub to adjust blade pitch; a propeller pitch piston positioned to translate within said hub and connected to said propeller blades such that translation of said propeller pitch piston rotates said propeller blades, said propeller pitch piston having two opposing faces and biased on one face by a spring and biased on the opposing face by a supply of hydraulic fluid; a tube secured to said propeller pitch piston to translate therewith and to supply said hydraulic fluid; a servo piston positioned to translate within a housing, said servo piston dividing said housing into first and second chambers and having a first opposing surface and a second opposing surface, said first and second opposing surfaces being biased by hydraulic fluid in said first and second chambers respectively; a first bored shaft secured to translate with and extending from said first opposing surface of said servo piston, said first bored shaft extending from said housing to receive said tube such that said tube is translatable relative to said first bored shaft; a second bored shaft secured to translate with and extending from said second opposing surface of said servo piston, said second bored shaft extending out of said housing and containing a fluid exhaust port; and means for opening and covering said fluid exhaust port to a low pressure return to adjust blade pitch.