Opalko V. Substantiation of operational parameters of threaded joints of grain seeders

Comprehensive study of the technical level of grain seeders from the point of view of the life cycle stages of engineering, structural and functional approach was carried out in the dissertation. The system analysis of the design of the СЗ seeder, ASTRA testifies that many components of the machine at different levels of complexity have threaded connections, the largest number of them is fixed in the tank system, which has the highest priority in the number of performed functions. The obtained dependences show that the integrity of the threaded joints is determined by the properties of the integral elastic-damping system and is provided by its frequency, dissipative characteristics. Theoretical and experimental studies of nonlinear processes of oscillations of threaded joints with a gap, seeds in a box of a seed drill are carried out on the basis of original theoretical models and new experimental techniques. The quality indexes of threaded joints of seeders under the operating conditions are justified, the method of their evaluation, the maps of their parameters measurements are developed. A program and method for studying of the spectral characteristics of vibrations of threaded joints of grain seeders under the field conditions and experimental laboratory studies of threaded joints have been developed. The technical level of grain sowers of type СЗ, ASTRA from the point of view of conformity to the design normative requirements at their designing, operation and service is determined. Recommendations are developed to improve the quality of threaded joints as seeders and other agricultural machines.