The dynamic performance of shearer cutting part is improved from two aspects of rocker box structure optimization and multi-stage gear three-dimensional topology modification

① In order to improve the low-order natural frequency, the structure of the rocker box is optimized, and the deformation of the rocker box and the meshing error of the gear pair are significantly reduced under the steady load and impact load.

② Combined with system dynamics simulation and fine tooth contact analysis, a new method of multi-stage gear 3D topological modification is proposed. By using this method, the peak value of contact stress and dynamic load coefficient of each gear pair in the cutting section under rated working condition are significantly reduced.

③ The influencing factors and rules of the optimum tooth profile modification and the optimum tooth profile modification are analyzed. The results show that the optimal tooth profile modification has a linear relationship with the tooth load and meshing error when the partial tooth surface separation does not occur; the deformation of support system and tooth profile modification will reduce the meshing stiffness of single tooth and increase the optimal tooth profile modification.

④ Reducing the fluctuation of static transmission error is a recognized principle of tooth profile modification. The peak to peak value of static transmission error (PPTE) and the harmonic amplitude combination of static transmission error (CHTE) can evaluate the fluctuation degree of static transmission error. The similarities and differences between the two evaluation indexes are compared. The results show that the tooth profile modification calculated by minimizing PPTE is less than that calculated by CHTE The results show that the dynamic load coefficient of the gear designed with minimum CHTE is less than that of the gear designed with minimum PPTE.