Analysis of natural characteristics of differential 2K-H epicyclic gear train for coal shearer

To overcome the adaptation difficulty of traditional coal shearer with constant cutting speed,a new cutting transmission system of coal shearer with cutting speed regulation was proposed. In order to understand the performance of this cutting transmission system,the translational-rotational dynamic model of non-coaxial differential 2K-H epicyclic gear train was established with lumped-parameter. Analysis of natural characteristic indicates that the classical rotation- al mode and translational mode do not exist while the planet mode remains;low-order natural frequencies were mostly decided by support stiffness while high-order natural frequencies were mainly affected by mesh stiffness,and they were collectively influenced by mesh stiffness of external gear pair in sequence in different areas. The general expression of mesh frequency of 2K-H planetary gear set was derived,which was proportional to the speed difference between ring gear and sun gear. Analysis results can be used in shearer design and provide a reference for cutting speed regulation in this new coal shearer.