Tribodiagnostics of aircraft reduction gear elements

The paper is devoted to the tribodiagnostics of the technical condition of aircraft reduction gear elements (exemplified by the aircraft gear box). The following methods of testing the parameters of wear products are used: atomic-emission spectroscopy (ASTM D 6595-00), ferrography (ASTM D7690 – 11), dispersion and morphological analysis (ASTM D – 6786 – 002).  Experimental and design increased and admissible-limit values of concentrations of wear product  elements and particles in the lubricant oil have been determined by statistical analysis of 120 lubricant samples selected in the process of rig testing of ten gears of five  KSA-33M  accessory gear boxes. Statistical analysis of the samples has been carried out to determine the maximum permissible, increased and normal values of diagnostic parameters of wear and to carry out their standardization. As a result, design values of increased concentration (IC) and maximum permissible concentration (MPC) of wear elements and particles in the lubricant oil of the KSA-33M accessory gear box have been found. A method of tribodiagnostics of components of the KSA-33M accessory gear box has been developed on the basis of the research carried out and the data obtained earlier. The method makes it possible to assess the technical condition of the part without its disassembly and removal from the aircraft, and, in case of any deviations from the norm, to predict its running hours before the state of emergency.