Research On Fretting Wear And Bearing Capacity Of Planetary Frame Axle Hole

In order to reduce fretting wear of planetary frame axle holes in practical engineering applications,designers often adopt interference fit to increase normal compressive stress between contact surfaces according to their own experience standards,so as to reduce the wear amount by reducing the relative slip amplitude between interference fit surfaces.However,this method lacks a certain theoretical basis,taking the interference as an example.When the interference is too small,a large relative fretting slip would be produced under the action of heavy load and time-varying excitation;the relative friction between contact surfaces would cause serious wear between the contact surfaces of axle holes.When the wear amount accumulated to a certain limit,the fretting slip at axle holes would be aggravated.When the wear accumulates to a certain extent,it would affect the performance of the planetary frame structure,cause the tearing of the left and right sides of the planetary frame and the rib column,and lead to the phenomenon of teeth beating between the solar wheel and the planetary wheel.Thus,the planetary gear reducer would be damaged and its service life would be Shortened.In view of the phenomenon of fretting wear at the interference joint of the axle hole of a planetary frame,it was studied of the problem of the wear depth of the interference joint of the axle hole of the planetary frame,and a discretization depth wear correction calculation method was proposed based on Archard model and finite element analysis.The process of a meshing period of the planetary gear train was simulated and analyzed by using ANSYS software.The effect of grid sensitivity on the finite element analysis of fretting wear was studied.The wear parameters of the joints corresponding to the Interference fitting face of the planetary frame axle hole was extracted by using APDL language to compile the post-processing program.Ultimately,the regularities of distribution of the relative slip state and stress of fretting wear surface were obtained,and the dangerous location of the fretting wear on interference fitting face was predicted.The results showed that the slip velocity of the interference fitting face was sensitive to the mesh quality of contact surface.When the number of grids was 500,the convergence speed and the accuracy of calculation could be guaranteed.The dangerous position of the interference fitting face appeared at the contact edge of the inner hole of planetary frame,and Increasing friction coefficient of contact surface could reduce fretting wear of the interference surface of the planetary frame shaft hole.A new type of interference fit method of planetary frame axle hole with rectangular spline was designed.Compared with the traditional interference fit structure of axle hole,the peak value of fretting wear of the joints of interference fit surface decreased by an order of magnitude,and the overall fretting wear distribution was more uniform.The fretting wear of the interference surface of planetary frame axle hole with different tooth number was analyzed.The results showed that the fretting wear in the axial direction was not sensitive to the number of mating teeth.The more teeth matching number in circumferential direction,the worse fretting wear of interference fit on tooth surface.