Dynamics Analysis And Study On The Optimization Of Driving Mechanism For The Boom System Of A Wet Shotcreting Machine

Abstract:Wet shotcreting machine is a kind of important engineering equipment in the spray anchor support field. Its boom system (also called spraying manipulator) is mainly used for adjusting the direction and position in spraying. But the unreasonable design of driving mechanism’s geometric parameters causes that the needed driving force is too large in luffing process, which leads to heavy workload for hydraulic system and great energy consumption in working et al.Focusing on the above problem, this paper took a kind of wet shotcreting machine’s boom system as an example. The optimization study on driving mechanism of the boom system was performed based on its dynamic model. In order to reducing driving force in the process of working of the boom system. The details were as follows:(1) Three-dimensional modeling was built and analysis of the boom system’s mechanism was done. The analysis shows that this boom system is a12-link mechanism which is an incomplete open chain (including two closed-loop mechanism).(2) Lagrange’s dynamical equations were used to establish the dynamic model of the boom system, which was the analytical model of the boom system’s driving force. And the dynamic model was verified by using the software of PRO/E.(3) According to the above dynamic model, the impact of driving mechanism’s geometric parameters on driving force of the boom system was analyzed. The results show that driving force should be further optimized. And based on the dynamics analysis of wet shotcreting machine under different working conditions, the extreme conditions was got.(4) Based on the dynamic model of the boom system, the objective was to minimize the maximum driving force under extreme conditions. And the constraint was to ensure the movement space and work performance. So the optimization model of the boom system’s driving mechanism was built. The optimization model was solved by using genetic algorithms. The optimized maximum driving force of the upper arm reduced by18.36%relative to the original, and the optimized maximum driving force of forearm relatively reduced by40.27%.(5) The three-dimensional modeling of the boom system was rebuilt by using the new parameters of the optimized driving mechanism. The driving force of the optimized boom system was verified by using simulation experiments. The results show that the optimized driving force of the boom system significantly reduces relatively. In addition, the experimental method of measuring the hydraulic cylinders’oil pressure was used to verify the analytical model of the boom system’s driving force. The results indicate that the driving mechanism of the optimized boom system is feasible.This paper’s research is a reference to build the dynamic model of an incomplete-open-chain mechanism and optimize the driving mechanism for engineering equipment.