An oil transfer assembly supplies oil into a moving, rotating tube extending along an axis. The assembly is provided with a support plate transversal to the axis and a sleeve, which is angularly fixed with respect to the support plate, it is configured to be coupled in a sliding and watertight way to a terminal section of the inlet of said tube and has at least one chamber for transferring oil into said terminal section of the inlet. The assembly is also equipped with at least two tubular bodies, which project axially from the support plate, define between them an annular channel communicating with the chamber and join the sleeve to the support plate in a watertight manner and with clearances so as to leave freedom of orientation of the sleeve around any direction orthogonal to the axis.

An oil transfer assembly supplies oil into a moving, rotating tube extending along an axis. The assembly is provided with a support plate transversal to the axis and a sleeve, which is angularly fixed with respect to the support plate, it is configured to be coupled in a sliding and watertight way to a terminal section of the inlet of said tube and has at least one chamber for transferring oil into said terminal section of the inlet. The assembly is also equipped with at least two tubular bodies, which project axially from the support plate, define between them an annular channel communicating with the chamber and join the sleeve to the support plate in a watertight manner and with clearances so as to leave freedom of orientation of the sleeve around any direction orthogonal to the axis.

The assembly (25) links a static housing (24) of the turbomachine, into which supply lines, in particular fluid supply lines (23), arrive, to the blades of the propeller, and comprises: a system for controlling fluid pitch (27), rigidly connected to the static housing (24), capable of being linked to the supply lines, a linear actuator (28) having two chambers separated by a piston (71) of which the sliding is dictated by the control system and allows the blades to rotate, and two concentric tubes (36, 37) housed in the planetary shaft of the epicyclic reduction gear and linking the system (27) to the actuator (28) by delimiting two fluid passages (45, 48) linked, respectively, with the two chambers (72, 73) of the actuator.

The assembly (25) links a static housing (24) of the turbomachine, into which supply lines, in particular fluid supply lines (23), arrive, to the blades of the propeller, and comprises: a system for controlling fluid pitch (27), rigidly connected to the static housing (24), capable of being linked to the supply lines, a linear actuator (28) having two chambers separated by a piston (71) of which the sliding is dictated by the control system and allows the blades to rotate, and two concentric tubes (36, 37) housed in the planetary shaft of the epicyclic reduction gear and linking the system (27) to the actuator (28) by delimiting two fluid passages (45, 48) linked, respectively, with the two chambers (72, 73) of the actuator.

The variable pitch propeller assembly includes a hub. The variable pitch propeller assembly also includes a plurality of propeller blade assemblies spaced circumferentially about the hub. Each of the plurality of propeller blade assemblies configured to rotate a respective propeller blade. The variable pitch propeller assembly also includes a hydraulic fluid port assembly integrally formed and including at least three hydraulic fluid ports configured to receive respective flows of hydraulic fluid from a stationary hydraulic fluid transfer sleeve. The variable pitch propeller assembly also includes a pitch actuator assembly coupled in flow communication with at least three hydraulic fluid ports through respective hydraulic fluid transfer tubes. The pitch actuator coupled to the plurality of propeller blade assemblies to selectively control a pitch of the propeller blades. The pitch actuator assembly includes a travel stop configured to limit a rotation of at least one of the pitch actuator assemblies.

The variable pitch propeller assembly includes a hub. The variable pitch propeller assembly also includes a plurality of propeller blade assemblies spaced circumferentially about the hub. Each of the plurality of propeller blade assemblies configured to rotate a respective propeller blade. The variable pitch propeller assembly also includes a hydraulic fluid port assembly integrally formed and including at least three hydraulic fluid ports configured to receive respective flows of hydraulic fluid from a stationary hydraulic fluid transfer sleeve. The variable pitch propeller assembly also includes a pitch actuator assembly coupled in flow communication with at least three hydraulic fluid ports through respective hydraulic fluid transfer tubes. The pitch actuator coupled to the plurality of propeller blade assemblies to selectively control a pitch of the propeller blades. The pitch actuator assembly includes a travel stop configured to limit a rotation of at least one of the pitch actuator assemblies.

A system and method for controlling an aircraft propeller are provided. In anticipation of a condition in which a parameter related to an angle of a plurality of blades of the propeller reaches a value beyond a predetermined threshold, a first control signal is output comprising instructions to actuate a feather valve operatively coupled to an actuator configured to adjust the angle in response to hydraulic pressure, thereby causing the feather valve to provide the hydraulic pressure to the actuator and the angle to be adjusted for bringing the parameter towards the threshold. When the parameter reaches the predetermined threshold, a second control signal is output comprising instructions to hold the feather valve at a position in which the hydraulic pressure is withheld from the actuator, thereby causing the angle to remain unchanged.

A pitch control assembly for adjusting the pitch of a propeller blade, including a pitch control unit comprising a housing, with a plurality of control valves and corresponding hydraulic lines located within the housing, a blade angle unit, a transfer bearing mounted to the housing and having a plurality of hydraulic lines fluidly coupled to the hydraulic lines of the pitch control unit, a transfer tube axially receiving and axially moveable relative to at least a portion of the transfer bearing, a magnetic core sleeve carried by the transfer tube and located within the blade angle unit.

A pitch control assembly for adjusting the pitch of a propeller blade, including a pitch control unit comprising a housing, with a plurality of control valves and corresponding hydraulic lines located within the housing, a blade angle unit, a transfer bearing mounted to the housing and having a plurality of hydraulic lines fluidly coupled to the hydraulic lines of the pitch control unit, a transfer tube axially receiving and axially moveable relative to at least a portion of the transfer bearing, a magnetic core sleeve carried by the transfer tube and located within the blade angle unit.

Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body. A plurality of piezo stacks is coupled to a first end of the primary spool, and applying a voltage to at least one of the piezo stacks causes an output stroke of the plurality of the piezo strokes for displacing the primary spool. The secondary spool is displaced together with the primary spool relative to the body if displacement of the primary spool relative to the secondary spool cannot occur.