| For calculating the strength and life of gear, the key step is to calculate the load and stress and their change process on the tooth accurately. But the study on the mechanics properties of gear mesh is still inadequate up to now.Taking an involute spur gear as example, this thesis analyzed the gear meshing process to derive the computation model of tooth bending deformation and contact elastic deformation, constructed deformation coordinated relationship to establish a precise calculation mechanical model of tooth loading. And then, through MATLAB software programming, solved the precise calculation model by complex trapezoidal integral method. For a specific example, calculated the change of tooth loading, tooth surface contact stress and tooth root bending stress in gear meshing process. Then studied the influences of some parameters on the mechanics properties of gear meshing. Through simulating the gear engagement by ANSYS software, gained the von Mises equivalent stress and maximum contact stress results of several gear meshing points, and calculated the contact teeth surface stress in initial meshing point and exiting meshing point, and compared them with theoretical calculated results to show that it is credible to calculate the tooth loading using the proposed calculation model in certain extent. Determined the dangerous position of gear contact fatigue and bending fatigue, and calculated the gear meshing load spectrum, tooth contact stress spectrum and bending stress spectrum in dangerous fatigue position for an example, and then calculated the gear fatigue life by using σ-N curve.The conclusions of this thesis will be helpful for further improving the calculating precision of involute spur gear mechanics properties and fatigue life in meshing process. |
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