Modeling And Safety Analysis Of Spur Gear System Based On Multi-platform Simulation

Gear is a kind of mechanical parts which is used to transmit motion and power. Since Euler improve traditional gear into involute cylindrical gear in 1760 s, gears have been widely used because of its high transmission efficiency, compact structure, large power transmission range and other irreplaceable advantages. Safety of gear system often determines the safety of powertrain and even the whole machine. With the development of high-speed rail technology, traction gear joint in the bogie gearbox is working in high-speed heavy load conditions continually, bearing the start-load and brake-load and other alternating loads coming with speed governing. Safety study on gear system is very important.After learning the basic theory and various academic research. Taking Argentine metergage DMUs gear box and its traction gear as research objects, the following aspects were investigated:First, the service life refers to the period from being put into use to gear system failure occurs.The bathtub curve shows that the random failure happens during this period. The components failure modes of the system are regarded as system elements, these modes have been added up and classified. The most important risk items have been picked out through the analysis. Using the Weibull Method to obtain the reliability of each risk element, and calculate the gear box system reliability finally.Second, according to the principle of gear meshing, through UG parametric modeling capabilities, we got single tooth profile curve which contains accurate tooth root transition curve. Use UG software to complete the tooth profile curve, and stretched it into a three-dimensional entity. Obtain the driven gear by the same method therewith. According to the design parameters, variable fact is introduced in the assembly position so as to avoid the undercut. And then a gear pair model is completed. Re-establishing the driving wheel wear model under conditions of normal wear, and the worn gear pair model is done after assembly.Third, after the establishment of a traction gear pair model, finite element analysis and meshing simulation analysis are solved based on ANSYS Workbench. The carrying capacity of the gears under individual working condition is worked out, with the same initial incentive, observe the carrying capacity of worn gear pair model under the same conditions so as to analyze their security. Under simulation environment of lubrication conditions, we can observe the effect of lubrication on the gear carrying capacity, and then analysis the safety of system. We can also analysis the different stress between the worn gear pair model and the normal gear pair model under lubrication.In summary, this thesis combined use computer-aided design software with UG and ANSYS Workbench, Taking Argentine meter-gage DMUs gear box and its traction gear as research objects, established an accurate model and safety analysis. So as to provide a reference for the detection and diagnosis of traction gear during actual runtime.