The Analysis And Experimental Research Of Gear Bending Fatigue Strength Influence Factors

Gear transmission is the most widely used mechanism in mechanical transmission,it has the advantages of the wide range of power, accurate transmission ratio, hightransmission efficiency, long service life, work safety, so it has been widely used inautomobiles, ships, aircrafts, wind power and other fields. The quality of its carryingcapacity directly affects the normal operation of the whole transmission system. Withthe rapid development of science and technology progress and industrial production, weput forward higher requirements on the bearing capacity of the gear transmission device,so the research on improving the gear bearing capacity has been paid more and moreattention. The bending fatigue strength of gears is an important index for evaluation ofbearing capacity of gears, and it is also the data base of gear design, so it is necessary tostudy the influence factors of gear bending fatigue strength for improving the bendingfatigue strength of gears, and then to improve the capacity of gears. This paper includesthe following aspects:①Based on the original scheme of gear tooth broken frequently weakness,combining with factors that affect the gear bending fatigue strength, puts forward twokinds of new schemes, and analyse the feasibility to improve the gear bending fatiguestrength of the two new schemes.②Based on the residual stress testing principle, select X-ray and fixed method as the detecting method to detect gear tooth root residual stress before and aftershot peening, comparative analyse of the gear tooth root residual stress results beforeand after shot peening, can obtain the the reliability of data that shot peening canimprove the residual compressive stress.③Randomly select from the gear samples of three kinds of schemes, do thebending fatigue test using the grouping method and the lifting and lowering method forthe bending fatigue test at Zwick rig, the power flow open test rig, and the fatigue lifedata sample size is discussed.④Use of probability and statistics theory to deal with the data of the fatigue life,and in accordance with the lognormal distribution, two parameter Weibull distributionand the three parameter Weibull distribution, and examine the degree of fitting. Finally,combined with the different stress level fatigue life data, fit the fatigue curves of the gear set of the three schemes and get the best scheme to improve the gear bendingfatigue strength.⑤Use FEM to simulate of the shot peening process that has the greatest impacton the gear bending fatigue strength in the two new schemes, verify that shot peeningcan improve gear tooth residual stress...