Research On Vibration Signal Modeling Method Of Planetary Gear Box Based On Fault Meshing Motion Characteristics

Planetary gear boxes are widely used in various large and complex mechanical equipment,such as wind power generation,helicopters,etc.However,long-term service and harsh operating environment make the key components in the planetary gearbox prone to different types and degrees of damage.These damages will affect the normal operation of the equipment,may cause major economic losses,and may even lead to major loss of life and other serious accidents.Therefore,it is particularly important to establish a perfect fault diagnosis method to ensure that the mechanical equipment can work stably and safely.The movement between the internal structures of the planetary gearbox is a typical composite movement.The meshing position between the gear teeth changes with the relative movement time between the gears.Especially,the sensor is installed on a fixed box,which makes the transmission path from the meshing vibration signal of the faulty gear teeth to the sensor time-varying.These factors increase the difficulty of fault diagnosis of planetary gearbox.Therefore,it is very important to study the complete evolution cycle of fault meshing motion characteristics,and then obtain complete fault information,accurately interpret the frequency components of vibration signals and establish a reasonable fault vibration signal model.In view of the above problems,this paper has carried out in-depth research,starting with theoretical modeling of vibration signals,fault meshing motion characteristics,spectrum structure analysis,formula derivation,simulation analysis and experimental verification,mainly including the following work:1.In view of the unique structure of the planetary gearbox and its complex internal motion characteristics,the transmission mechanism,fault mode,signal transmission path and the meshing position motion characteristics of the local fault point of the planetary gearbox are systematically introduced,which lays a theoretical foundation for subsequent research.2.Several traditional phenomenological modeling methods of vibration signals are introduced,and detailed comparisons are made from different factors that affect the modeling of vibration signals,providing reference and guidance for future research directions.Highlight the research object and main research points of the full text.3.On the basis of the work in 1 and 2,based on the periodic characteristics of the local fault tide and the periodic changes of the vibration signal transmission path,the local fault vibration signal model of the solar gear and the planetary gear is established,and the established model formula is deduced,and its frequency components are interpreted.4.In order to verify the correctness of the work of 1,2 and 3,the time domain and frequency domain diagrams of the local fault vibration signals of the sun gear and the planet gear are analyzed through tests,the existence of the tidal frequency is verified,and the tidal frequency can be used as a unique characteristic frequency in the planet gear box to diagnose the local fault of the sun gear and the planet gear.Through modeling and simulation,as well as analysis and comparison of experimental data,this paper proves the correctness of the vibration signal model built,thus providing a reference basis for fault diagnosis.