Research On Reliability Of Gear Hobbing Manufacturing Process For Transmission Gears

Cars have gradually entered thousands of households and become the most important way for people to travel,along with the rapid development of science and technology and economy.Transmission is one of the most important components of automobile.Its quality and performance directly determine the function and life of the automobile.Gear is the core part of automobile transmission,it plays the role of transmitting torque and bearing load in the working process of transmission.The quality,accuracy and reliability of gears are the key factors that restrict the performance of transmission.However,the research of gear reliability mainly focuses on its performance and service life.To solve this problem,this paper focuses on the reliability of gear hobbing manufacturing process,and analyzes and evaluates the key reliability influencing factors.First of all,this paper analyzes the reliability influencing factors of six aspects in the manufacturing process of transmission gear hobbing by using the 5M1 E analysis method,They are hobbing equipment,blank materials,processing methods,measurement and environmental factors.And the evaluation method is given for the two most critical factors that directly affect the quality of gear products: the stability of gear hobbing technology and the reliability of gear hobbing machine.Analysis and Research have been carried out on the stability of hobbing process.Aiming at the difficulties in obtaining dynamic parameters and determining the cutting thickness when the stable lobe diagram is applied to the stability analysis of gear hobbing,a stable lobe diagram is established while the modal and dynamic parameters in the diagram are obtained through the finite element simulation.The machining parameters and chatter frequency are determined by analyzing the vibration data of steady state cutting and chatter cutting,and The effectiveness of the stable lobe diagram whose parameters are obtained through simulation is verified,with the help of empirical formulas of feed rate and cutting thickness.Reliability evaluation of gear hobbing machine based on Bayes theory has been carried out to deal with the problem that the fault data of high-speed dry cutting hobbing CNC machine tool is rare,and it will take a long time and costs a lot of money to carry out reliability test with large sample size.Firstly,a large number of fault data of similar products have been tracked and analyzed,and the typical fault modes and causes have been analyzed.What's more,we have also put forward some suggestions to Improve these problems.Then,we employed a fusion method based on Kullbank information to get the fusion prior distribution.In addition,we built the machine tool state detection system,and carried out.At last,we combined the fusion prior distribution and test sample according to Bayesian theory to get the posterior distribution and reliability inference could be conducted based on it.