Research On Modeling And Minimizing Method Of Efficiency Loss Of TBM Planetary Reducer Gear Train

The full face hard rock tunnel boring machine(TBM)is a special tunnel boring engineering equipment integrating machine,electricity and fluid,which is widely used in rock stratum excavation.However,in the actual construction,it is found that the power loss is serious,which leads to the high environmental working temperature and difficult treatment.The typical driving system of roadheader is composed of multiple planetary gear trains and multi-stage fixed-axis gear trains,and the driving path is complex.And in the process of involute gear transmission,the meshing efficiency of gear pairs accounts for a large proportion,so the loss of meshing transmission efficiency is reduced,or an effective way to reduce the transmission power loss.In this paper,taking TBM planetary reducer gear train as the research object,the establishment method of its efficiency loss model is studied,and on this basis,its parameters are optimized with the goal of minimizing its efficiency loss,so as to achieve the engineering goal of energy-saving construction.To solve the problem of how to accurately calculate the transmission efficiency of gear meshing,the concept of equivalent slip ratio(Δζ_e)is put forward.According to the instantaneous efficiency,an accurate theoretical model of meshing efficiency loss(Δη=1-η)is established,and the equivalent relationship between the product of friction coefficient(μ)and equivalent slip rate and meshing efficiency loss(Δη=μΔζ_e)is obtained.Several examples of calculation of meshing efficiency loss of internal and external gear transmission and modified gear transmission are given,and some results of the algorithm are compared with instantaneous efficiency integral method or approximate calculation method of loss efficiency.The results show that the theoretical model of meshing efficiency loss is scientific and has no principle deviation;The derived two equivalent relations of meshing efficiency loss and equivalent slip rate are concise,and the algorithm is correct and the calculation is accurate.In view of the serious power loss during the construction of TBM main cutting system,aiming at energy saving,the efficiency optimization design of the widely used two-stage2K-H TBM planetary reducer gear train was carried out.The efficiency loss model of 2K-H planetary gear train is established by using the self-established calculation formula of gear meshing efficiency loss and the inversion method.On this basis,the efficiency loss model of two-stage 2K-H TBM planetary gear train is obtained.Taking this gear train as an example,the limitations and constraints in the design process of 2K-H planetary gear train are analyzed and classified and simplified.On this basis,the mathematical model is established under the objective function of the highest efficiency and the smallest relative sliding under the constraint conditions of tooth matching,coincidence degree,tooth thickness,undercut and interference,and the tooth number and modification coefficient are optimized in two stages.Self-developed software is used to verify the interference of optimization results.The results show that the efficiency loss of TBM planetary reducer can be reduced by 4%-6%through two-stage optimization under the constraint conditions of gear matching and modification coefficient.The total energy saving is considerable.The relative sliding between tooth surfaces is reduced,and the working performance of gears is further improved to a certain extent.In view of the characteristics of large transmission ratio and high transmission efficiency of planetary reducer with small tooth difference,the structure with small tooth difference is proposed as the main reducer of TBM propulsion structure.Four alternative basic configurations are put forward,and the transmission ratio and meshing efficiency are analyzed by the reverse method.Considering that the combination of teeth meets the transmission ratio error,the optimal design is carried out by referring to the design method of internal meshing in the previous chapter.The results show that the efficiency loss is reduced by 50%.The structure size is reduced by 15%,and the optimization effect is remarkable,which has important reference significance for TBM reducer mechanism innovation.