A tip gap monitoring system for a ducted aircraft having a proprotor system including a duct and a plurality of proprotor blades includes sensors coupled to the proprotor system. The sensors are configured to detect one or more parameters of the proprotor system to form a plurality of sensor measurements. The tip gap monitoring system also includes a flight control computer in data communication with the sensors. The flight control computer includes a tip gap measurement module configured to determine a tip gap distance between the duct and the proprotor blades based on the sensor measurements.

Rotor hubs having pitch control systems and related methods are disclosed herein. An example apparatus includes a housing including a first housing arm to support a first blade grip and a first blade spindle and a second housing arm to support a second blade grip and a second blade spindle. The example apparatus includes a first pitch link and a second pitch link. The example apparatus includes a first pitch arm coupled to the first pitch link and one of the first blade grip or the first blade spindle and a second pitch arm coupled to the second pitch link and one of the second blade grip or the second blade spindle. The second pitch arm is to extend past the first housing arm to couple with the one of the second blade grip or the second blade spindle.

Rotor hubs having pitch control systems and related methods are disclosed herein. An example apparatus includes a housing including a first housing arm to support a first blade grip and a first blade spindle and a second housing arm to support a second blade grip and a second blade spindle. The example apparatus includes a first pitch link and a second pitch link. The example apparatus includes a first pitch arm coupled to the first pitch link and one of the first blade grip or the first blade spindle and a second pitch arm coupled to the second pitch link and one of the second blade grip or the second blade spindle. The second pitch arm is to extend past the first housing arm to couple with the one of the second blade grip or the second blade spindle.

A gearbox including an angular contact ball bearing comprising a first row of balls provided with a plurality of balls, a second row of balls provided with another plurality of balls, at least one inner ring and at least one outer ring. According to the invention, in a degraded operating mode of the bearing, the first row of balls is configured to transmit at least one first axial force oriented along a first axis and at least one second axial force oriented along a second axis opposite the first axis, the second row of balls transmitting no axial force.

A propeller provided with interchangeable blades, and to a method of mounting such interchangeable blades on the propeller. The propeller comprises a hub, fastening fittings, rotation guide devices for guiding the fastening fittings in rotation relative to the hub, locking parts, and blades. The fastening fittings are configured to be assembled into the hub from the inside of the hub, and the locking parts lock respective ones of the fastening fittings onto the hub. The blades are fastened to respective ones of the fastening fittings outside the hub and can thus easily be replaced with other blades without removing the propeller.

A propeller provided with interchangeable blades, and to a method of mounting such interchangeable blades on the propeller. The propeller comprises a hub, fastening fittings, rotation guide devices for guiding the fastening fittings in rotation relative to the hub, locking parts, and blades. The fastening fittings are configured to be assembled into the hub from the inside of the hub, and the locking parts lock respective ones of the fastening fittings onto the hub. The blades are fastened to respective ones of the fastening fittings outside the hub and can thus easily be replaced with other blades without removing the propeller.

Low latency pitch adjustable rotors are disclosed. A disclosed example rotor includes a rotor hub to rotate about a rotational axis, rotor blades coupled to the rotor hub, the rotor blades being pitch adjustable and having corresponding pitch angles, and a reaction hinge operatively coupled between the rotor hub and the rotor blades, the reaction hinge to move relative to the rotor hub in response to an angular acceleration or deceleration of the rotor hub to adjust the pitch angles.

Low latency pitch adjustable rotors are disclosed. A disclosed example rotor includes a rotor hub to rotate about a rotational axis, rotor blades coupled to the rotor hub, the rotor blades being pitch adjustable and having corresponding pitch angles, and a reaction hinge operatively coupled between the rotor hub and the rotor blades, the reaction hinge to move relative to the rotor hub in response to an angular acceleration or deceleration of the rotor hub to adjust the pitch angles.

The present invention relates to a fan rotor with variable pitch blades, comprising a rotor disc, equipped at its periphery with a plurality of rotary fasteners (16), each fastener (16) comprising a cell (17) for receiving the root (150) of a blade (15). This rotor is characterised in that an elongated wedge (2) and a prestressing rod (3) with at least one cam (33) are also arranged in each cell (17), the bottom of the cell (17) comprising as many retraction cavities (173) as the rod (3) comprises cams (33), in that the prestressing rod (3) is interposed between the wedge (2) and the bottom (171) of the cell (17), so that said cam (33) is facing a corresponding retraction cavity (173) and in that the prestressing rod (3) can rotate about its longitudinal axis (X2-X′2), between a rest position, in which the cam (33) is housed in the retraction cavity (173), and an armed position, in which the cam (33) exerts a radial pressure on the central region (22) of the wedge (2) so as to move the wedge (2) towards the blade root (150).

A Pulsed Locomotor (120), for propelling media, fluids and crafts, in fluids and on land, comprising a blade (124) securely connected to a drive shaft (122). Upon reciprocation, the ambient medium is forced towards the trailing edge of the blade (124) thereby causing a reactive locomotion of the apparatus, substantially along the plane of the blade. Apparatus is secured to motor M by fastening through aperture (130). The apparatus can be operated directly by motor M, and indirectly by the reaction momentum imparted to a supporting platform P. Thrust is directed by steering handle (128) about a bearing (126), rotatably coupling to platform P and base C. Lubricant L is supplied to outlets (134) via conduit (136) and inlet (132), to coat the apparatus with a lubricant cavity, for drag reduction. The blade (124) planes along a figure 8 reciprocation path s1e1s2e2s1. Crafts are embodied.