Patent ID: 6474598
Filing Date: 2002-11-05
Classification: B64C,F16F

Abstract:
A suspension and shock absorber for a retractable landing gear of an aircraft, comprising:a cylinder having a first end and a second end; a piston located in the cylinder, the piston having a rod extending outward from the second end of the cylinder, the piston dividing the cylinder into first and second chambers that change in volume as the piston moves within the cylinder; a magneto-rheological hydraulic fluid located within the first chamber of the cylinder and in contact with a first side of the piston; a pressurized gas mixed with the hydraulic fluid within the first chamber; a pressurized gas in the second chamber in contact with a second side of the piston; an orifice in the first chamber of the cylinder, through which the hydraulic fluid flows as the piston moves relative to the cylinder; an electromagnetic coil mounted to the orifice for generating an electromagnetic field in the orifice to alter a viscosity of the hydraulic fluid flowing through the orifice due to movement of the piston toward the first end of the piston toward the first end of the cylinder; and a controller for dynamically controlling the electromagnetic coil with respect to a deceleration pressure of the cylinder and a position and velocity of the piston and if the velocity is sufficiently high, for setting the deceleration pressure to hold the stress of the material of the cylinder during deceleration of the piston at a level that would cause permanent deformation without immediate failure.