Analysis Of Friction Power Of Spiral Bevel Gear Of The Main Reducer

Spiral bevel gears are important transmission parts of the main reducer,of which the transmission energy loss will directly affect the efficiency of the main reducer and transmission system.At present,the research of spiral bevel gear is mainly concentrated in the optimization of machining process and the improvement of precision.But its meshing power and transmission efficiency are not widely studied around the world.With the increasing demand of energy saving and emission reduction,how to reduce the energy consumption of the transmission system is especially urgent.Therefore,it is of great practical significance to establish the meshing power and transmission efficiency mesh of spiral bevel gears.According to the main influencing factors of gear meshing power,a theoretical model of friction power loss under mixed lubrication was established based on the analysis the relative velocity,load distribution,minimum oil film thickness and friction coefficient of meshing surface at home and abroad.Through the MATLAB software carries on the simulation analysis,and compares with the existing research results to verify the accuracy of the computational model.The main research works are as follows:Firstly,a reasonable mathematical model of spiral bevel gear was established.From the point of view of gear machining,the machining coordinates of pinion and gear are established respectively.According to the relative motion between the gear and the cutters,based on the kinematics is deduced by coordinate homogeneous transformation matrix through envelope relationship between cutter and tooth surface.Then the tooth surface equation is established by using the gear meshing principle,and the 3D coordinate value of tooth surface is solved by MATLAB.Secondly,the contact point of the spiral bevel gear was transformed into the linear contact along the discrete points along the elliptical axis of the contact region.Considering the main parameters model of the tooth surface,such as load distribution,roughness and lubricating oil parameters,the calculation formulas of dynamic friction coefficient of gears under mixed lubrication was deduced according to the actual working condition in the process of gear meshing,which was a combination of elastohydrodynamic lubrication and boundary lubrication.Finally,the friction power calculation model of spiral bevel gears in mixed lubrication was established.The model was simulated and in MATLAB,and the meshing power and transmission efficiency of two different transmission conditions with different load torque and different rotational speeds of same load torque were calculated,and the rationality of the friction model was verified by comparing with the existing research results.