Transmission Accuracy Reliability Analysis And Optimization Of Planetary Reducers Considering Gear Wear

High-end equipment manufacturing is the core link lies in the industry chain under the lead of high and new technology.As the main parts of high-end equipment manufacturing,reducers play significant roles in it.The transmission accuracy is one of the important indexes to measure the performance of reducers.However,the dynamic gear wear during the working process leads to poor transmission accuracy and low reliability,which influences the transmission accuracy of system and restricts the performance of the high-end equipment.Therefore,it is of great significance to analyze the influencing factors of the transmission accuracy,and it is also important to carry on the reliability analysis and the optimization design.Taking a two-stage 2K-H planetary gear reducer as an example,this thesis has carried out four aspects of transmission error modeling,numerical simulation of gear wear,time-variant transmission accuracy reliability analysis and the optimization design of the planetary gear reducer,the specific research contents of this article are as follows:(1)Based on the meshing line analysis method,a transmission error model of the planetary gear reducer is established which considers the manufacturing eccentric error,installation eccentric error,and some short-period errors such as individual circular pitch error,tooth profile deviation,and tooth thickness deviation.The transmission error in this model is performed by the equivalent mesh errors on the meshing line.(2)Based on Archard's wear model and Hertz contact theory,a numerical calculation model is established.Wear coefficient and relative moving distance are calculated.What's more,the normal load at the mesh point is solved through the kinetic equations which are based on lumped parameter approximation.According to some wear loss samples from the numerical calculation model,the accumulation wear loss of each gear in the life expectancy of the reducer is predicted based on Gaussian Process.(3)Aiming at the errors and the gear wear stochastic process,an improved time-variant reliability analysis method based on stochastic process discretization was used to solve the transmission accuracy reliability of the planetary gear reducer.According to the analysis results,the trend of the transmission accuracy reliability of the planetary gear reducer with time is obtained.(4)With the minimum machining cost as the optimization object and reliability of transmission accuracy and gear wear loss as the constraint conditions,the model of reliability-based optimization design is proposed.And the sequential quadratic programming method is used to obtain the optimum tolerance allocation.After the reliability-based optimization design,the transmission accuracy reliability reaches 99.33% which is 10.96% higher than that before,the machining cost is reduced by 3.8%.Through the transmission accuracy reliability analysis and the optimization design of the planetary gear reducers,the machining cost is reduced under the requirements of transmission accuracy reliability and gear wear loss,which provides an efficacious method for the selection of tolerance during the process of manufacturing.