Los A. Provision of durability of movable skew-symmetric and extreme loaded units of aircraft assemblies

The scientific and practical problem of provision of movable skew-symmetric extreme loaded units' durability based on the wear of antifriction coatings in friction zones and fatigue life of attaching subassemblies is solved. For estimation of efficiency of assemblies of the considered type the following criteria are offered: - Limit operability under friction; - Limit durability. In particular it is established, that such antifriction coating as tungsten carbide is the most suitable for movable joints, main parts of which are made of titanium alloy ВТ-22 or maraging steel ВКС-170, as considering the parameters of limit operability and durability it competes with electrolytic hard chrome, and considering the technological and ecological conditions (RoHS of the EU and OSHA of the USA) surpasses it. The offered method allowed providing the designated durability of movable assemblies: - During development of future airplanes the design and manufacturing parameters of the considered units were formulated providing the unit durability equal to the durability of the attached assemblies - To modify short service life movable assemblies of nose and main landing gear of the AN-140, AN-148 and AN-158 by the optimization of organic-composite and metallic bushings application providing for the increase in wear resistance; - To modify short service life assemblies of nose landing gear steering of the AN-26, AN-30 and AN-32 airplanes providing a three-time increase of fatigue life.