Aircraft landing gear assembly with electromechanical actuation and aircraft provided with such assembly
A landing gear assembly, having an electromechanical device for actuating the landing gear and locking and releasing device, includes: a rotary actuator acting on the assembly at the hinge point, having a rotary electric motor connected to an actuating arm, to rotate the assembly around a respective actuation axis with an interconnection so that, in case of power supply failure, the actuator is free to rotate dragged by the assembly by free fall; and a linear actuator, integral to the assembly and movable therewith, and which includes a rotary electric motor and a cam mechanism to transform rotary motion of the motor into an axial motion of a locking pin. The actuation axes of the rotary actuator and of the linear actuator are parallel, and the rotation axis of the rotary electric motor of the linear actuator coincides with the linear actuation axis of the locking pin.
1. An aircraft landing gear assembly, having a device actuating the landing gear from a retracted position to an extended position and vice versa, and a device for locking and releasing in and from said positions, jointed to an aircraft at a respective hinge point, comprising:
a rotary actuator acting on the landing gear assembly at said hinge point, having a rotary electric motor connected to an actuating arm, for rotation of the landing gear assembly around a respective actuation axis, through a reduction gear group, with an interconnection so that, in case of power supply failure, the actuator is free to rotate dragged by the landing gear assembly by free fall;
a linear actuator, integral to the landing gear assembly and movable therewith, which constitutes said locking device and which comprises a rotary electric motor and a cam mechanism to transform a rotary motion of the electric motor into an axial motion of a locking pin according to a respective actuation axis, acting in retraction opposed to a spring which determines the extension thereof in a position for locking the landing gear assembly ( 1 ), wherein the actuation axes of the rotary actuator and of the linear actuator are parallel, and wherein the rotation axis of the rotary electric motor of the linear actuator coincides with the linear actuation axis of the locking pin.
2. The landing gear assembly according to claim 1 , wherein said linear actuator is assembled on a projecting extension of the landing gear assembly, extending on a plane parallel to a plane defined by the wheels of the landing gear assembly.
3. The landing gear assembly according to claim 1 , wherein the reduction gear group of the rotary actuator comprises harmonic gears and Hall effect sensors assembled on a printed circuit providing an output to the controller of the arm position.
4. The landing gear assembly according to claim 1 , wherein the rotary actuator comprises a brushless type electric motor fed by using Hall effect sensors, comprising a rotor whereon there are permanent magnets which produce uniform magnetic fields between the poles and then the excitation flows; and a stator whereon three phases are arranged which are energized by producing, in turn, an electromagnetic field.
5. The landing gear assembly according to claim 1 , wherein the linear actuator comprises a double winding brushless electric motor, fed by using Hall effect sensors, coupled to a cam mechanism used to convert the motor rotary motion into the linear motion of the locking pin.
6. The landing gear assembly according to claim 5 , wherein in the linear actuator a magnetic sensor provides a signal when the locking pin is in wholly retracted position.
7. An aircraft comprising at least one of landing gear assemblies of claim 1 .