Analysis Of Nonlinear Vibration Of Rolling-rotor System For Satellite Gyroscope

As a key device of satellite navigation system, the performance of satellite gyroscope largely depends on the performance of gyroscope rotor system. With the rapid development of satellite technology, design of gyroscope rotor system is developing toward high speed and light weight. This structure is key reason for emerging instability frequently. Due to the complexity of the rotor system and the strong nonlinear factor, the past linear theory and research methods have been no longer suitable for modern rotor system design and analysis. To carry out the nonlinear vibration analysis of gyroscope rotor system has important academic significance and application value.In this paper, the object of study is satellite gyroscope rolling bearing-rotor system. First of all, a nonlinear dynamics model of gyroscope rotor system considered nonlinear bearing force and the impact of oil film is presented based on the analysis of bearing kinematics theory, Hertz elastic contact theory and elastic fluid lubrication theory. The bifurcation diagrams, the Poincaré maps, the frequency spectrums, the phase diagram and the axis orbit in different parameters of rotor system are solved by Runge-Kutta method to research the influence of different parameters on the nonlinear vibration of rotor system. These results are further verified by the maximum Lyapunov exponents of system. Studies show that rich periodic, non-periodic(quasi-periodic and chaotic) vibrations and period doubling bifurcation exist in this system with the change of the rotor system structure and working parameters. Instability of the system can be reduced by selecting reasonable parameters, such as speed, damp, radial clearance, the number of rolling elements and radial force.Then a dynamic model of rolling bearing-rotor system with surface waviness is presented. The nonlinear vibration characteristics of system with different amplitude and wave number waviness in inner and outer raceway are studied. Also the nonlinear vibration characteristics of system at different rotation speed are studied. Studies have shown that with the increasing of waviness wave number, vibration intensity of system also increases, and when the wave number and the number of rolling elements are the same, the system appears serious vibration. When considering the influence of surface waviness in outer raceway, the system is mainly through period-doubling bifurcation to chaos. When considering the influence of surface waviness in inner raceway, there is a functional relationship between vibration frequency of rotor system, wave number and the number of rolling elements. When considering the influence of surface waviness in inner and outer raceway, with the increasing of speed, the system exhibits quasi-periodic response and chaotic motion and is mainly through quasi-periodic bifurcation to chaos.Finally using self-designed test device to verify the accuracy of the presented dynamic model by testing the relationship between radial force and natural frequency of system. According to the data of theoretical analysis and test, with the increasing of radial force, the natural frequency of system increases gradually. And the greater the radial force is, the better the data of theoretical analysis and test fit.