The main feature of the framed landing gear frame landing gear is that it connects the wheel to the wing or fuselage through a bearing frame. The rods and the shock absorbing strut in the bearing frame are hinged to each other. They only bear axial forces (in the direction of their respective axes) without being subjected to bending moments. Therefore, the structure of the landing gear has a simple structure and a small mass, and has been widely used in light low-speed aircraft in the past. However, modern high-speed aircraft are basically not used because of the difficulty in retracting.
The main feature of the strut-type landing gear strut type landing gear is that the shock absorber and the bearing strut are combined, and the wheel is directly fixed to the piston rod of the shock absorber. The connection between the upper end of the shock absorbing strut and the wing depends on the retraction requirements. For the retractable landing gear, the struts can double as a retractable actuator. The torque is transmitted through the torsion arm and can also be transmitted by a spline connection between the piston rod and the inner wall of the cylinder of the shock absorbing strut. This type of landing gear is simple and compact in construction, easy to retract, and low in quality, and is one of the widely used forms on modern aircraft. The disadvantage of the strut type landing gear is that the piston rod not only bears the axial force but also bears the bending moment, so it is easy to wear and jam, and the sealing performance of the shock absorber is deteriorated, and the large initial pressure cannot be used.
The main feature of the rocker landing gear rocker landing gear is that the wheel is connected to the piston rod of the shock absorber via a rotatable rocker arm. The shock absorber can also double as a bearing strut. This type of piston only bears the axial force and does not bear the bending moment, so the sealing performance is good, the initial pressure of the shock absorber can be increased to reduce the size of the reducer, and the disadvantage of the pillar type is overcome, on the modern aircraft. Has been widely used. The disadvantage of the rocker type landing gear is that the construction is complicated and the joint is subjected to a large force, so that it is also worn during use.