Intelligent Optimization Design of the Cutting Unit’s Transmission System of a Shearer Based on Robustness

Abstract

To improve the robustness of the shearer cutting part and reduce the manufacturing cost, in this study, the gear transmission system of a shearer’s cutting unit can be divided into three basic components: single-gear-on-one-shaft form, the planetary reduction form, and double-gears-on-one-shaft form. The dynamic differential equations of each structure are established in this study, and the volume functions of the three basic components are obtained. The characteristics of the internal excitation of the gear transmission system are analyzed, and a scheme for solving the motion parameters of each component is formulated based on the harmonic balance method. Based on the parameters, such as tooth width, tooth number, and modulus, as optimized variables, a robust optimization method minimizing the multi-parameter evaluation function, which is weighted linearly by dimensionless vibration and volume of the gear transmission system, is presented. The gear transmission system of a sample shearer’s cutting unit is optimized using the proposed method. The results show that the transmission system’s size decreases by 5.4%, the drum’s maximum torsional acceleration decreases by 17.8%, and the first gear’s maximum torsional acceleration decreases by 9.6%. Thus, we conclude that the optimum design method decreases a shearer’s manufacturing cost and decreases the cutting unit’s failure rate.