A ram air turbine (RAT) system can include a fluid circuit, a turbine, a shaft connected to the turbine to turn with the turbine, and a hydraulic pump connected (e.g., directly) to the shaft and connected to the fluid circuit to pump fluid within the fluid circuit. The hydraulic pump can be a variable displacement pump, for example (e.g., configured to govern a speed of the shaft and turbine). The hydraulic pump can be used to power and provide speed control to an electric generator.

Power generation systems for aircraft are described. The power generation systems include at least one aircraft component and a ram air turbine assembly configured to provide power to the at least one aircraft component. The ram air turbine assembly includes a turbine, a power generator operably connected to the turbine, and a continuously variable transmission arranged between the turbine and the power generator, the continuously variable transmission configured to receive an input rotational speed from the turbine and output a constant output rotation speed to enable power generation at the power generator.

Disclosed is an air cycle machine (ACM) having: a turbine; a compressor; a compressor shaft connected to the compressor and configured to receive rotational energy from a gearbox; and a turbine shaft connected to the turbine and configured to provide rotational energy to the gearbox; wherein the turbine shaft and the compressor shaft operate at different rotational speeds.

Disclosed is an aircraft system comprising: a linkage comprising a first end, an opposing second end and a clevis therebetween; a motion limiter configured to engage the clevis; wherein: the first end is configured for connecting to one of a strut of a ram air turbine (RAT) and an enclosure door, and the second end is configured for connecting with another of the strut and the door; and the motion limiter limits rotation between the first end of the linkage and the second end of the linkage.

An actuator release mechanism comprising a longitudinal member, e.g. a piston, which is moveable axially to permit or prevent axial movement of the lock bolt and hence deployment of the actuator. Movement of the piston is due to the force of the lock bolt, under a spring force, on the one hand, and to the position and force of a linkage assembly on the other hand. The linkage assembly comprises a first link fixed, at one end, e.g. by means of a piston lock pin, to the piston and fixed at a pivot point to a second link. The second link is fixed to a rotational drive means, here a rotary solenoid or stepper motor, so as to rotate about a centre of rotation.

A hydraulic damping device includes a housing defining a fluid inlet and a fluid outlet, a damping plate disposed within the housing, the damping plate including a plurality of damping holes defined therethrough and positioned to allow fluid communication between the fluid inlet and the fluid outlet, and a blocking member disposed within the housing and configured to rotate relative to the damping plate to progressively block the damping holes.

A ram air turbine has turbine blades connected to rotate a transmission shaft. The transmission shaft is connected to drive a first gear which is engaged to drive a second gear. The second gear is connected to rotate an output shaft extending through a strut away from the transmission shaft. A governor arrangement is configured to change a pitch angle of the blades in response to speed, and includes counterweights acting on a spring in the governor arrangement. The governor spring is positioned on an opposed side of the strut relative to the turbine.

A locking mechanism comprises a piston element comprising a piston groove extending in an axial direction along a radially outer surface of the piston element, a housing comprising a bore for receiving the piston element for reciprocating axial movement between a locked position and an unlocked position, a locking ball received in the piston groove and a locking ring mounted for rotational movement about the piston element between a locking position and an unlocking position, the locking ring comprising a radially inner locking ring groove, the locking ring groove having a recess formed in a radially inner surface thereof for receiving the locking ball in the unlocking position of the locking ring. The piston groove comprises a first axially extending section and a second axially extending section, the radial depth (D1) of the first axially extending section being greater than the radial depth (D2) of the second axially extending section.

A toggle release mechanism comprises a base element and a toggle element rotatably mounted at a first end to the base element about a first axis for rotation between a first, locking position and a second, release position. The mechanism further comprises a link element mounted at a first end to a second end of the toggle element about a second axis parallel to the first axis. The first end of the toggle element comprises a first stop and the base element comprises a second stop opposed to the first stop. The first stop and the second stop are in contact when the toggle element is in its locked position, preventing rotational movement of the toggle element in one rotational direction.

A protective coating composition for providing protection to a component of a ram air turbine system in need thereof. The protective coating composition comprises an aqueous-soluble or alkaline-soluble polymer matrix, one or more compressible fillers, and one or more non-compressible fillers. The disclosure also provides a method for providing a protective coating onto components of a ram air turbine system in need thereof for providing indentation and scratch resistance thereto.