| Gear rotor system plays an important role in the actual production and daily life,at the same time it is also one of the most widely application in the mechanical transmission system.However the research of spur gear rotor system is the base of researching Gear rotor system,In order to better use this system,gear fault is necessary to research,in all kinds of gear faults the spalled fault is a common one of gear pairs.It is also main failure for closed gear system.So this paper researches gear system with spalled fault in Meshing and Vibration characteristics.Specific content as follows:(1)All kinds of analytical models for time-varying mesh stiffness(TVMS)calculation of spur gears are researched,and this paper further gives all kinds of analytical models with spalled faults and compares their TVMS and vibration response.Researches show spalled fault makes TVMS reduce in the scope of it and with different models the reductions are similar.With considering more factors the analytical results are more approached to the actual meshing,in the other words,the results of analytical and finite element models are more approached to equal.(2)Considering the effects of extended tooth contact(ETC),revised fillet-foundation stiffness under double-tooth engagement region,nonlinear contact stiffness and tooth regional spalling defect,a crosscutting analytical model for TVMS calculation of regional spalled spur gears is established.The proposed model is also verified by comparing the TVMS under different single spalling widths,lengths,locations and depths with that obtained from finite element method(FEM).Researches show that analytical models get the similar results with the FEM when the spalled width is small,with the increasing of spalled width the changes of TVMS are more and more sudden at the end and start of the spalling,especially in the single tooth meshing area.(3)A crosscutting analytical model for TVMS calculation of banded spalled spur gears is established,and then compared its results with the results of coupling FEM.On the whole,no matter rectangle or oval spalled analytical models have the same tendencies with FEM.With the same spalled lengths of different shapes have different tendencies of TVMS curve,the result of rectangle spalling rises a sudden changing at the starting and ending of the spalling,results of oval spalling are the largest in the three shapes.Results with the same spalled area are familiar with the same length.(4)Finally,this paper establishes a vertical cutting analytical model by vertical cutting cantilever beam model and compares it with the crosscutting analytical model and the FEM,the vertical cutting analytical model is more suitable for banded spalled gears.Researches show that for partial spalling,the results of vertical cutting analytical model have the same tendencies with the results of crosscutting analytical model,for banded spalling,the results of vertical cutting analytical model are more familar with the results of FEM than the results of crosscutting analytical model. |
