An electro-hydraulic circuit includes a supply line that connects between a hydraulic supply device that supplies hydraulic fluid and a driving part to be driven by a hydraulic pressure of the hydraulic fluid; a switching valve disposed in the supply line to switch between switching lines for the hydraulic fluid supplied to the driving part; a pilot hydraulic line connected to the switching valve to supply the hydraulic fluid for switching between the switching lines; a check valve disposed in the pilot hydraulic line; a solenoid valve disposed in the pilot hydraulic line to change a supply state of the hydraulic fluid to the switching valve; a sealing material disposed in the switching valve to seal the hydraulic fluid; and a relief valve disposed in the pilot hydraulic line to release the pilot hydraulic pressure

A rotor blade includes an actuator comprising an electric motor having a rotary drive shaft, a bearing for mounting the rotary drive shaft along an axis extending along the length of the rotor blade, and a lubrication system for lubricating the bearing. The lubrication system includes a sump closer to the tip of the blade than the bearing, and a pump for pumping lubricant from the sump to the bearing.

An electro-hydraulic circuit includes a supply line that connects between a hydraulic supply device that supplies hydraulic fluid and a driving part to be driven by a hydraulic pressure of the hydraulic fluid; a switching valve disposed in the supply line to switch between switching lines for the hydraulic fluid supplied to the driving part; a pilot hydraulic line connected to the switching valve to supply the hydraulic fluid for switching between the switching lines; a check valve disposed in the pilot hydraulic line; a solenoid valve disposed in the pilot hydraulic line to change a supply state of the hydraulic fluid to the switching valve; a sealing material disposed in the switching valve to seal the hydraulic fluid; and a relief valve disposed in the pilot hydraulic line to release the pilot hydraulic pressure

A closeout structure for a rotor blade includes a first fluid channel for supplying a first pressure to a first port of a trailing edge (TE) device, a second fluid channel for supplying a second pressure to a second port of the TE de vice, and a trough disposed between the first fluid channel and the second fluid channel. The closeout structure forms a double-W shape.

An electro-hydraulic on-blade actuation system includes a pair of linear motors, a pair of flexible bladders and a pair of hydraulic units. Each linear motor outputs linear force in response to input. The pair of flexible bladders attach to opposite sides of a rotorcraft blade. Each hydraulic unit connects a linear motor to a flexible bladder to hydraulically transmit the linear force of the linear motor to the flexible bladder to actuate the rotorcraft blade.