In the work, a detailed analysis of the structures of power equipment of airplanes and power plants is carried out according to the directions of their application. According to the data of the analysis, the technologies of design and use of electric drives on the territory of Ukraine received their greatest development and practical application in the field of power engineering (hydrogenerators and hydrogenerator-motors), but these technologies are almost not used in new designs of aircraft power equipment.
It is highlighted that the structural elements of hydrogenerators work under complex load conditions caused by the joint action of inertial forces from the rotation of the rotor, gravitational forces, assembly loads arising from the seating of parts with tension, as well as temperature loads. When analyzing the trend lines and operating modes of hydraulic units, it was found that the rotation of the rotor, the unevenness of the electromagnetic field, and the hydraulic effect on the turbine lead to the vibration of the entire structure of the hydraulic unit as a whole. The causes of loads and vibrations and their impact on the structure of the unit are correlated with the impact of loads and vibrations on the power equipment of the aircraft, which occur during its flight and are caused by the inherent fluctuations of the aircraft structure, forced vibrations from the rotational frequency of the aircraft engine and the very frequency of rotation of the drives.
The method and scientifically based principles of reducing the number of failures and refurbishment of the power equipment of aircraft equipment and airfield energy equipment have been developed on the basis of the following scientific research methods: retrospective method (allows to analyze existing repair technologies and calculation methods of electric machines), methods of mathematical modeling of the stress-strain state in three-dimensional setups for determining mechanical stresses and forces in different modes of operation of electric machines, methods of mathematical modeling of finite elements for determining the thermal state of units of electric machines during technological operations and in different operational modes, methods of numerical processing of experimental results based on statistical algorithms, methods of redefinition of objects to ensure the possibility of applying technologies for repairing hydrogenerators for aerospace power equipment.
The analysis of the vibration state of hydraulic units in different operating modes was carried out, the main experimental vibration parameters and their compliance with the requirements of regulatory documentation were determined.
The measurements of the shapes of rotors and stators of hydrogenerators-motors were made. According to the results of the analysis of the shapes by numerical methods (using the decomposition of the shape into the Fourier series), the estimated deviations of the existing shapes from the cylindrical shape were determined.
On the basis of the test results (considered in Section 3), measures are proposed to increase the reliability of hydrogenerators-motors during their reconstruction.
The study of the stress-strain state of the rotor of the hydrogenerator-motor was carried out by the analytical method, as well as by the finite element method using the appropriate software (SolidWorks Simulation application package). At the same time, both the state of the rotor before the reconstruction and the stresses and deformations of the rotor elements that will arise in the process of performing works on its reconstruction are considered.
Scientific novelty of the work:
1. The justified approach and the developed calculation of the stress-strain state of the hydraulic unit in the three-dimensional setting with clearly defined boundary conditions of the first and third kind, taking into account the modes of operation at rated, overspeed and acceleration speeds.
2. Refinement of the parameters of the hydrogenerator refurbishment technology based on the three-dimensional modeling, which relies on step-by-step problem solving with an iterative step and gradual differentiation of the correctness of the computation results.
3. The possibility of repairing power equipment of aircraft equipment due to the use of technology from the field of general power engineering has been established.
Practical significance of the obtained results:
1. The technology for refurbishment of the power equipment of aircraft equipment has been developed, which ensures the maintainability of units in airfield conditions.
2. Calculated parameters of technological operations, which make it possible to determine the necessary parameters (stresses, landing forces, etc.) based on mathematical modeling.
3. The established patterns of deformation of equipment parts and assemblies make it possible to determine their possible performance and different modes of operation during further operation.
