Abstract: A twin engine, coaxial, dual-propeller propulsion system employing a unique transmission having two independent drive trains. The first of the two engines exclusively drives a first drive train, which in turn rotates a forward multi-bladed propeller assembly. The second engine exclusively drives a second drive train, which in turn rotates an aft multi-bladed propeller assembly. Thus, the propellers of this propulsion system, even though coaxial, are driven by separate engines. The propulsion system also enjoys the increased propulsive efficiency of a coaxial dual-propeller design as the first drive train rotates the forward propeller assembly in a first rotational direction and the second drive train rotates the aft propeller assembly in the opposite direction. Further, the propulsion system employs pitch change control mechanisms which independently control the respective pitch of the blades of the two propeller assemblies.

Abstract: A propeller unit, each blade (1) being fixed to a blade foot (2) rendered integral with a hub (3) rotating around an axis but mobile with respect to the hub on translation in the direction of the axis and rotating around a second axis orthogonal to the first axis, this foot (2) being moreover rendered integral with an arch (5) in translation but free with respect to the arch on rotation; a pitch modifier is linked to the arch to translate the arch along the spin axis of the hub (3); the hub (3) and each blade foot (2) have members (8, 23) for activating the feet in rotation provoking from translation of the arch (5) the rotation of the blade feet around an axis mobile on translation in the same direction and orthogonal to the blade feet.

Abstract: A variable pitch propeller module includes first and second multi-bladed propellers arranged to be driven in opposite rotational directions by a reduction gear mechanism, via shafts. First and second drums are rotatably mounted on the hubs of the first and second propellers and the drums are arranged to rotate the blades of the propellers. A hydraulic motor is mounted coaxially on and rotates with the second propeller, the hydraulic motor being arranged to drive the drums by via a pitch change gear assembly. A hydraulic fluid feed tube extends coaxially through the reduction gear mechanism and both propellers to supply hydraulic fluid to the hydraulic motor. An annular sleeve is positioned coaxially on the tube. The hydraulic fluid feed tube has passages and the sleeve has passages which are aligned to allow hydraulic fluid to flow to the hydraulic motor to vary the pitch of both blades. The feed tube and sleeve are moved axially to control the flow of hydraulic fluid to the hydraulic motor.

Abstract: An arrangement for the adjusting of rotor blades of a propfan turboprop engine equipped with two counter-rotating propfan rotors has a number of double-toothed planet wheels which are fastened in a rotatably disposed web. The web is supported on the side of the housing by planet members disposed on one of the propfan rotors. The two toothings of the planet wheels are in operative connection with ball spindle adjusting rings. Using an adjusting motor, a relative movement of the web can be achieved with respect to the housing, whereby the blades of two counter-rotating rotor blade rings can be swivelled. According to the invention, an adjustment of rotor blades will also be possible when no stationary housing parts are available for the support.

Abstract: A lightweight counterrotatable propeller system driven by a rotatable shaft is disclosed. The system includes first and second counterrotatable propellers, each propeller including a plurality of blades mounted on first and second hubs, respectively. Each blade is attached to the hub by means of a ball screw which converts centrifugal force on each of the rotating propeller blades into a pitch changing force. Gearing means for operatively connecting the shaft with each propeller are located between the propellers with a carrying member for one of the propellers forming an outer wall which radially bounds the gearing means. Additionally, non-rotating actuating means for changing propeller pitch are operatively connected to the blades of each of said first and second propellers through first and second thrust bearings, respectively.

Abstract: A propeller module for an aero gas turbine engine comprising two contra-rotating propellers has a reduction gear train positioned axially between the propellers. Pitch change mechanism are provided to change the pitch of the blades of both propellers independently of the differential speed of the propellers. The pitch change mechanisms comprise two sets of hydraulic motors one set of which is mounted on a carrier member of the gear train within the planet gears, the other set is mounted on the hub of the second propeller. Pitch selector valves control the supply of hydraulic fluid to the hydraulic motors, and the pitch selector valves are operated by a pitch change power unit. The pitch selector valves are positioned coaxially of the propellers and a transfer tube extends coaxially between the pitch selector valves to transfer hydraulic fluid therebetween independently of differential speed of the propellers.

Abstract: A propeller module for a gas turbine engine comprising two contra-rotating propellers has a reduction gear positioned axially between the propellers. Pitch change mechanisms are provided to change the pitch of the blades of both propellers independent of the differential speed of the propellers.

Abstract: A pitch-change apparatus for a ducted thrust fan having a plurality of variable pitch blades employs a camming ring mounted coaxially of the hub at an axially fixed station along the hub axis for rotation about the hub axis both with the blades and relative to the blades. The ring has a generally spherical outer periphery and a plurality of helical camming grooves extend in a generally spherical plane on the periphery. Each of the variable pitch blades is connected to a pitch-change horn having a cam follower mounted on its outer end, and the camming ring and the horns are so arranged about the hub axis that the plurality of followers on the horns engage respectively the plurality of helical camming grooves. Rotary drive means receives pitch-change commands from an appropriate controller and rotates the camming ring relative to the blades to cause blade pitch to be changed through the cooperative operation of the camming grooves on the ring and the cam followers on the pitch-change horns.

Abstract: An axial flow fan wherein the cylindrical housings for the shanks of blades are mounted on a flat plate-like circular base of the hub which is rotated by an electric motor through the medium of a belt transmission and a hollow shaft. The motor, transmission and shaft are mounted at one side and the housings are mounted at the other side of the base.

Abstract: Marine propulsion equipment for installation in a ship or boat comprises a screw propeller with variable-pitch blades, mounted on one end of a propeller shaft whose other end is coupled to the output flange of a reversible speed-reduction gearbox. A pitch control rod is connected at one end through a linkage to the blades and extends within an axial bore in the shaft, the rod being longitudinally movable by a hydraulic actuator between predetermined limiting positions corresponding respectively to a coarse-pitch setting and a fine-pitch setting of the screw blades. The actuator is of piston-and-cylinder type interposed between the output shaft of the gearbox and the adjacent end of the propeller shaft as a part of the drive train. The actuator cylinder is formed either in a half-coupling which connects the shaft to the gearbox output flange, or in a separate tubular capsule which is itself connected between the half-coupling and the gearbox output flange.