초록

An electro-hydraulic proportional servoactuator is disclosed which has built-in fail-safe systems which cause the power turbine nozzles to return to a zero degree angular position in the event of either an electrical system failure or a hydraulic system failure, and features a toggling effect.

대표청구항 ▼

An electro-hydraulic proportional actuator, comprising: a housing including a cylinder, said cylinder having ports for admitting hydraulic fluid to said cylinder, at a first port at one end of said cylinder, and at a second port at the other end of said cylinder; piston means movably installed in sa

An electro-hydraulic proportional actuator, comprising: a housing including a cylinder, said cylinder having ports for admitting hydraulic fluid to said cylinder, at a first port at one end of said cylinder, and at a second port at the other end of said cylinder; piston means movably installed in said cylinder, said piston means having an output shaft coupled for movement therewith at said one end of said cylinder, said piston means being driven toward said other end of said cylinder when pressurized fluid is admitted through both said first port and said second port; valve means means for admitting pressurized fluid to said cylinder, said valve means having selectable flow portions in which no fluid is admitted to said cylinder, fluid is admitted only through said first port, or fluid is admitted is admitted through both said first and second ports, said valve means being operable to cause said piston means to be driven to any of an infinite number of positions; a solenoid coupled to produce a first force to drive said valve means to a selected flow position corresponding to an incremental change in the electrical control signal supplied to said solenoid; and feedback means responsive to the movement of said piston means, for producing a second force opposing said first force, said second force also coupled to drive said valve means; said feedback means comprises: a lever arm 120 pivotably connected to said housing, said lever arm also being pivotably connected to said output shaft 94 so any movement of said piston means in said cylinder causes a corresponding translation of said lever arm about said housing; and means 130 operably connected to said level arm for transmitting said second force from said level arm to said solenoid; and wherein said means for transmitting comprises: a spring, one end of said spring being connected to and moving with said lever arm, and other end of said spring being connected to the plunger of said solenoid.