In dynamic modeling, the cutting part of shearer is divided into two parts: transmission system and rocker box. The transmission system is composed of cutting motor, cutting transmission system (including fixed, bearing, gear shaft, planetary gear train) and cutting drum. Taking the whole cutting part as the object, a multi-stage gear transmission box coupling dynamic model is established, which can comprehensively study the dynamic performance of the cutting part, the influence of rocker box on gear meshing and the transmission of excitation in the system.
A large number of gear dynamic models adopt the hypothesis of small deformation
1) Assuming that the deformation of the supporting system is very small, the influence of the translation of the gear centroid on the meshing angle and theoretical meshing interval of each thin-walled gear pair is ignored;
2) Assuming that the tooth deformation is very small, the difference between the actual meshing interval and the theoretical meshing interval is ignored. However, the accuracy of the dynamic model decreases with the increase of support system and tooth deformation.
At present, the research on gear dynamics under the condition of large deformation of supporting system and gear teeth has been carried out in academic circles, but these researches are limited to plane problems. Therefore, the three-dimensional gear dynamic model considering both the support system and the large deformation of the gear teeth (referred to as the large deformation gear model) is proposed in this section, which provides a more precise gear model for the coupling dynamic modeling of the shearer cutting part.