A boundary layer ingestion-open rotor system for use with an aircraft having a fuselage, wings, and an empennage includes an open rotor assembly, one or more energy storage systems, and an electronic control unit (ECU). The open rotor assembly includes fan blades connected to and extending radially from a rotor hub, and a linkage assembly connecting the hub to the fuselage aft of the empennage within a predefined boundary layer of airflow around the fuselage. The energy storage systems are connectable to the rotor hub. In response to an electronic control signal, the system(s) selectively energize the open rotor assembly to cause rotation of the hub to occur within the boundary layer. The ECU selectively generates the electronic control signals to energize the open rotor assembly during one or more predetermined flight operating phases of the aircraft, e.g., cruise, takeoff, landing, and descent.

A lock system for a landing gear assembly may comprise a housing and a hook configured to rotate relative to the housing. A lock pin may be configured to translate into a rotational path of the hook. An electromechanical actuator may be configured to translate the lock pin.

A lock system for a landing gear assembly may comprise a housing and a hook configured to rotate relative to the housing. A lock pin may be configured to translate into a rotational path of the hook. An electromechanical actuator may be configured to translate the lock pin.

A landing gear lifting/lowering EHA system includes: a hydraulic actuator configured to lift and lower the leg of an aircraft; at least one electrically operated hydraulic pump; a hydraulic path; a pressure sensor attached to the hydraulic actuator or the hydraulic path and configured to output a measurement signal corresponding to hydraulic pressure; and a controller configured to output a control signal to the electrically operated hydraulic pump, wherein, when a state in which the hydraulic pressure exceeds a set pressure continues for a set time, the control unit stops the electrically operated hydraulic pump in operation and resumes the operation of the electrically operated hydraulic pump after the hydraulic pressure drops to or below a second set pressure after the electrically operated hydraulic pump is stopped.

A landing gear lifting/lowering EHA system includes: a hydraulic actuator configured to lift and lower the leg of an aircraft; at least one electrically operated hydraulic pump; a hydraulic path; a pressure sensor attached to the hydraulic actuator or the hydraulic path and configured to output a measurement signal corresponding to hydraulic pressure; and a controller configured to output a control signal to the electrically operated hydraulic pump, wherein, when a state in which the hydraulic pressure exceeds a set pressure continues for a set time, the control unit stops the electrically operated hydraulic pump in operation and resumes the operation of the electrically operated hydraulic pump after the hydraulic pressure drops to or below a second set pressure after the electrically operated hydraulic pump is stopped.

Embodiments of the present invention relate to the technical field of aircrafts, and provide an undercarriage and an unmanned aerial vehicle (UAV) having the undercarriage. The undercarriage includes a power assembly and an undercarriage body. The power assembly includes a connecting member and a drive apparatus for driving the connecting member to reciprocate. The undercarriage body includes a plurality of hinged connecting rods, the plurality of hinged connecting rods constituting at least one parallelogram mechanism, and projections of at least two of the hinged connecting rods on a side face of the fuselage are staggered. The undercarriage body is connected to the connecting member, and when the connecting member reciprocates, the undercarriage body is driven to be folded or unfolded. In the foregoing manner, driven by the reciprocating motion of the connecting member, the undercarriage body may be retracted and folded on two sides or in an interior of the fuselage, so that the undercarriage may be retracted and folded during flight of the UAV, thereby avoiding unnecessary resistance in the air.

Embodiments of the present invention relate to the technical field of aircrafts, and provide an undercarriage and an unmanned aerial vehicle (UAV) having the undercarriage. The undercarriage includes a power assembly and an undercarriage body. The power assembly includes a connecting member and a drive apparatus for driving the connecting member to reciprocate. The undercarriage body includes a plurality of hinged connecting rods, the plurality of hinged connecting rods constituting at least one parallelogram mechanism, and projections of at least two of the hinged connecting rods on a side face of the fuselage are staggered. The undercarriage body is connected to the connecting member, and when the connecting member reciprocates, the undercarriage body is driven to be folded or unfolded. In the foregoing manner, driven by the reciprocating motion of the connecting member, the undercarriage body may be retracted and folded on two sides or in an interior of the fuselage, so that the undercarriage may be retracted and folded during flight of the UAV, thereby avoiding unnecessary resistance in the air.

A system for controlling landing gear subsystems may comprise a controller and a first motor drive unit in operable communication with the controller. A first electric motor and a second electric motor may be in operable communication with the first motor drive unit. A second motor drive unit may be in operable communication with the controller. A third electric motor and a fourth electric motor may be in operable communication with the second motor drive unit. An AC/DC converter may be electrically coupled to the first drive unit and the second motor drive unit.

A system for controlling landing gear subsystems may comprise a controller and a first motor drive unit in operable communication with the controller. A first electric motor and a second electric motor may be in operable communication with the first motor drive unit. A second motor drive unit may be in operable communication with the controller. A third electric motor and a fourth electric motor may be in operable communication with the second motor drive unit. An AC/DC converter may be electrically coupled to the first drive unit and the second motor drive unit.

A method of operating an electromechanical actuator includes coupling an inner portion of a split ball screw with an outer portion of the split ball screw, rotating the split ball screw about an axis to drive a ball nut in a first axial direction, in response to a failure mode of the electromechanical actuator, decoupling the outer portion of the split ball screw from the inner portion of the split ball screw, and translating the outer portion of the split ball screw and the ball nut in a second axial direction.