Research On Shafting Active Oil Supply Technology Based On Microfluidic Piezoelectric Injection

With the improvement of China’s comprehensive national strength,the demand for the development of space resources has been increasing,and Chinese space technology has made certain progress.With the national space strategy project and the demand for civilian satellite launching,the frequency and the number of satellite launching in China have increased in recent years.However,it requires more money and labor and material resources for the the development and launching of satellites.Therefore,it is necessary to improve effectively the life for service of the satellites in orbit.As the life of electronic components increasing,the main reason for restricting the life of satellites in orbit is the friction failure of mechanical components.The important reason for friction failure is that the attitude-controlled flywheel is in a lean and semi-lubricated state due to the untimely supply of lubricating oil.With the demand for satellite orbital life extension,the traditional passive oil supply lubrication has been unable to meet the requirements.Therefore,it is necessary to propose a reliable,controllable and long-term supplemental active oil supply method.Piezoelectric materials have the advantages such as short response time,small droplets and high controllability.Therefore,a high-precision active oil supply scheme for shafting can be designed based on the characteristics of piezoelectric materials.In this thesis,the piezoelectric micro-jet technology at home and abroad is introduced and analyzed.A piezoelectric micro-injection active fuel supply device integrated with shafting structure is proposed.It was designed to solve the bearing lubrication problem of satellite flywheel shafting structure.The main functions of oil storage,fuel supply and fuel injection can be realized,and the corresponding axial positioning function can also be realized.In this thesis,a hybrid design of ring piezoelectric oscillator and shafting structure is adopted.It can realize the function of oil supply and positioning in limited structure space.The design adopts contraction vibration mode to improve injection performance.In this thesis,the excitation signal of piezoelectric micro-spray is simulated and analyzed.The ANSYS software is used for frequency response and transient analysis of structures.The resonant characteristics of micro-jet structure and the variation of nozzle sound pressure under different excitation conditions are obtained.The ANSYS and FLUENT software are used.The fluid-solid coupling simulation analysis is carried out to obtain the injection state of the fuel oil under different excitation conditions.The injection process of the whole droplet is simulated,an d the velocity and volume of the droplet movement under different excitation parameters are analyzed.Optimized excitation parameters are obtained by analysis,and driving waveform of excitation signal is determined.And the driving power supply of piezoelectric oscillator is designed.The DC flyback boost circuit and half-bridge inverter circuit are designed,and the feasibility of the design circuit is determined by simulation analysis.And i draw the physical objects of PCB.The vibration modes of piezoelectric oscillator are analyzed experimentally and compared with the results of simulation analysis to determine the correctness of simulation analysis.Experiments were carried out to verify the feasibility of the active fuel supply device and the reliability of simulation analysis.The injection volume and velocity were measured to verify the influence of the excitation signal on the injection performance.The validity of bearing lubrication was verified by active oil supply lubrication experiment,and the optimal oil supply and the variation curve of friction moment at different rotating speeds were obtained.