Abstract: A pressure relief device for preventing over pressurization of a propeller hub is disclosed. The pressure relief devices is designed to fit within a ball hole opening in the hub arm of the hub. The pressure relief device includes a housing which sealably interfaces with an inner wall of the ball hole opening and a pressure relief insert which sealably interfaces with the housing. The pressure relief device includes a plurality of fracture tabs which engage an end of the housing exposed to hub cavity pressure. The fracture tabs are designed to break at a design pressure allowing the pressure relief insert to be forced out of the housing thus breaking the seal between the pressure relief insert and housing thereby venting the hub cavity.

Abstract: A pressure relief device for preventing over pressurization of a propeller hub is disclosed. The pressure relief device is designed to fit within a ball hole opening in the hub arm of the hub. The pressure relief device includes a housing which sealably interfaces with an inner wall of the ball loading hole opening and a diaphragm which sealably interfaces with the housing. The diaphragm is designed to rupture at a design pressure thus venting the hub cavity.

Abstract: A brush block assembly, for providing stationary mounting of electrically conductive brushes in contact registration with associated slip rings of a rotating interface, comprises a main housing adapted for mounting in proximity to the rotating interface and having a recess portion for releasably engaging a brush holder, and a brush holder formed from a thermoplastic molding compound comprising an organic polytetrafluoroethylene (PTFE) filler distributed within a polyetheretherketone (PEEK) thermoplastic resin, for securing the brushes within the recess in contact registration with their associated slip rings.

Abstract: A system for controlling propeller blade pitch is disclosed. The system comprises a transfer tube, wherein the transfer tube defines an element of the rotatable portion and wherein the transfer tube is non-translating relative the rotatable and non-rotatable portions. A transfer bearing for providing hydraulic fluid to and interfacing with the transfer tube is also used, wherein the transfer bearing is located on the non-rotatable portion. The system further includes a pitch change actuator and a mechanism form for actuating the pitch change actuator, wherein the mechanism is fluidically connected to and translatable relative to the transfer tube. A device for measuring blade angle of the propeller blade is also provided, wherein the device is separate and distinct from the transfer tube.

Abstract: The brush block housing for providing stationary mounting of graphite composition brushes in contact registration with the rotating interface slip rings of an aircraft propeller deicing system, is formed from a thermoplastic molding compound comprising an organic polytetrafluoroethylene (PTFE) filler distributed within a polyetheretherketone (PEEK) thermoplastic resin, thereby minimizing non-functional abrasion of the brushes.

Abstract: A blade angle feedback system for use with a propulsion system having a plurality of angularly adjustable blades, wherein each of the blades has an axis of rotation and is rotatable about the axis of rotation through a plurality of blade angles. The system includes a mechanism for indicating blade angle position of each of the sensed blades. The mechanism for indicating is movable through the plurality of blade angles with the blades, wherein the mechanism for indicating has a plurality of identities depending on and indicative of the blade angle. Mechanisms for designating a plurality of reference positions on the blades of the propulsion system and relative the mechanism for indicating are also provided.

Abstract: The hydraulic propeller system of the present invention has a central hub including a stationary portion and a rotatable portion. A plurality of propeller blades are connected with the rotatable portion, wherein each of the plurality of propeller blades has an adjustable pitch and a counterweight biasing the blades in a first pitch direction. An actuating mechanism is used for adjusting the pitch of each of the plurality of propeller blades. And a valve for locking the propeller blades at a last commanded pitch is further provided. At least the valve and the actuating mechanism are located on and rotatable with the rotatable portion.