Abstract: The vibration characteristics of a long wall shearer’s cutting unit gearbox (SCUG) are mostly investigated by theoretical models， however， these results are lacking in experimental validation. For validating theoretical results and investigating some nonlinear dynamic characteristics of SCUG， a dedicated test set-up which can simulate the real coal mining process is developed to operate the long wall shearer in loaded and unloaded working conditions. Vibration severity is taken as a comparison standard of theoretical and experimental results. Cutting depth， traction speed and coal hardness are considered as the experimental variables and the contributions of these factors to the vibration of SCUG are ranked. Coal hardness mutation， beat vibration phenomenon and motor run-up impact which can contribute to the resonance and fatigue damage of SCUG are analyzed in the experiment， and the impact of drum load on them is also quantified. The data obtained by the experiment and the relevant conclusions may provide a certain reference for the correct understanding of vibration response and reliability analysis of SCUG.

Key words: long wall shearer, vibration experiment, cutting unit gearbox, beat vibration phenomenon, dynamic characteristics