| In modern industry, gear transmission has been widely used as a traditional form of transfering movement and power.Gear design and manufacturing technology continues to move forward. The logarithmic spiral bevel gear has a unique advantage that the helix angles of each point for tooth line are equal everywhere.This new form of gear can effectively solve some issues for instance the transmission is not smooth and the efficiency of power transmission is low, which are brought by the reason that the helix angle isn't equal. Thus it is necessary to deeply study this kind of gear in the design and meshing respects.Based on the number of geometric characteristics of logarithmic spiral bevel gear, this paper presents a new modeling method and successfully constructs the meshing model of logarithmic spiral bevel gear. Based on this, the gear meshing simulation analysis is operated with ANSYS/LS-DYNA software in order to obtain stress distribution in the process of tooth contact. The tooth contact stress and tooth root bending stress magnitude, stress distribution and variation of cloud are analyzed. According to the operation result of the numerical simulation,the paper derives the formulas of tooth surface contact stress and tooth root bending stress.This research works mainly in the following aspects:1. Based on the meshing theory and design theory of logarithmic spiral bevel gear, a pair of three-dimensional model of meshing gears will be created. The article proposes a new modeling method which includes three innovation spots. First, using two conical logarithmic spiral of which the included angle is 360/2Z to determine the space position of tooth profile curve, the involute curve can be precisely located. Second, the conical logarithmic spiral which coiled around in the pitch cone surface is used as swept into the trajectory so that tooth profile can be guaranteed accurately. Third, the scanning mix section is established in the normal plane of swept into the trajectory so that the tooth profile of each point normal plane for gear tooth is the standard tooth profile.2. Based on this, the gear meshing simulation analysis is operated with ANSYS/LS-DYNA software in order to obtain stress distribution in the process of tooth contact. The tooth contact stress and tooth root bending stress magnitude, stress distribution and variation of cloud are analyzed. Contacting engineering practice, the results are in-depth study. The correctness of the gear model is verified.Thus it can quickly assess the design and make changes, but also provide the theoretical basis for the gear strength check and engineering application.3. According to the operation result of the numerical simulation and the curve fitting theory, the tooth contact stress and tooth root bending stress formulas are derived by MATLAB software. From the view of numerical simulation, a new thinking way is opened up for the formula calculation of two kinds of stress. |
