Studys On The Influences Of Surface Micro Pitting And Wear On The Thermal EHL Of Involute Spur Gear

The model of the gear microscopic surface pitting and embossing are set up in thisthesis, and based on the multi-grid (MG) method and the multi-level multi-integration(MLMI) method, many influence factors such as transient effects, thermal effects andsurface wear of the material are considered in the model, selective analysis the thermalEHL numerical solution during the meshing process. The thesis mainly includes theseparts: the influences of a single microscopic surface pitting on the thermal EHL ofinvolute spur gear; the influences of continuous microscopic surface pitting on thermalEHL of involute spur gear; the transient thermal EHL of the wear of surface embossingof involute spur gear; the influences of continuous impact under the effects of dynamicload on the thermal EHL of involute spur gear.Firstly, according to relationship of the geometric and transmission of the involutespur gear, a transient thermal EHL model of the involute spur gear has been establishedby the considering of a microscopic pitting on the gear surface. Based on the multi-gridmethod, by changing the curvature of a micro-pit and the depth of the pit to get differenttopography, then an absolutely thermal EHL numerical solution of involute spur gear isobtained during the meshing process along the contact line.Secondly, considering the continuous microscopic surface pitting phenomena ofthe gear surface, a complete thermal solution of it’s meshing overall process has beenobtained, then analyze it’s effect on the gear lubrication action. By changing the powerto change the load pressure of the two meshing gears, in order to research the influenceof irregular impact load and inherent load of two meshing gears that is cased bymicroscopic pitting.Thirdly, based on the previous research of surface roughness, a numerical analysisof thermal solution of the two meshing gears in different degree of wear is solved, suchas the central film pressure、film thickness、peak temperature rise and friction coefficientalong the contact line when each of the two meshing gears in similar degree wearing,and compare the change of central film pressure and thickness along the contact lineand so do the several particular meshing points.Lastly, a continuous impulse impact is added in the meshing process. By changing the impulse frequency and the impulse amplitude, get the absolutely numerical solutionunder the continuous impact during the contact line of meshing.