Dynamic Analysis On The Multiple Active Pinions And Gear Transmission System Of Shield Tunneling Cutter Head

Earth pressure balance shield machine is widely used in the development and utilization of underground space, and shield cutter head driving system is one of the most important components. Cutter head driving system consists of hydraulic motor, main reducer, pinions and gear units. At present, the study of gear is mostly concentrated on the main reducer. Due to the multiple pinions and gear system which connected with the cutter head bear impact load of cutter head, is liable to undertake partial load, phenomena of resonance and broken teeth are hardly, and complex mechanical mechanism, study on multiple pinions and gear is rarely. In this paper, based on extensive research, the method for calculating earth pressure balance shield tunneling torque of cutter head is deduced, an experimental platform for driving system of cutter head is developed, and through theoretical analysis, simulation and testing methods, in-depth study of mechanical behavior between three pinions and the larger gear at the end of the cutter head driving system is made. The main results achieved are as follows:(1) According to the requirement of experimental platform for driving system of earth pressure balance shield, through analysis and calculation, a shield machine model is developed.(2) Under the condition of considering the bending-torsional coupled vibration, the lumped parameter model of single gear pair is established. Then, it is extended to the three pinions and gear driving system of shield machine. By analyzing the characteristics of gear transmission, the gear pair meshing stiffness based on trapezoidal wave is achieved.(3) By using FEM software ABAQUS, the finite element modal model for three pinions and larger gear of shield machine is established, the natural frequency and vibration of gear system is obtained. We establish a dynamic simulation model of gear driving system, and get each pinion’s stress nephogram, the dynamic meshing force curve, external work, kinetic energy and total energy of the system.(4) Based on multi-body dynamics software ADAMS, established a dynamic model of shield machine’s multiple small gear meshing with the center larger gear, get each pinion’s dynamic meshing force and larger gear’s acceleration under the influence of different factors. After comparing the results of simulation with the ideal condition, we find that the three small gears start out of sync, different center distance, impact load of the big gear, the number of pinions meshing with larger gear all have great influence on the meshing force, can cause the unbalanced load between each gear, exacerbate the large gear’s vibration at the same time.