Load Capacity Analysis And Bending Stress Measuring For Spiral Bevel Gear

Spiral bevel gear is an important element to realize the transmission of intersecting axis.It is widely applied in the transmission system of aerospace,ship,vehicle,machine tool and other equipment,because of its advantages,such as large overlap ratio,strong bearing capacity,low noise,smooth transmission and so on.tooth broken and pitting are the main failure forms.Therefore,the calculation of bearing capacity and its experimental research are particularly important.Based on the strength calculation standard of ISO and AGMA,the tooth contact and the tooth root bending strength are calculated respectively,and the results of the finite element analysis with the gear contact and the test results of the root bending stress are compared.Based on the results of the finite element contact analysis and the test value of the bending stress of the tooth root,the friction coefficient of the tooth surface for spiral gears in the non lubricated and oil l ubricated state is reversed by using the multi-island genetic algorithm.The main content are as follows:(1)Gear modelling of spiral gear is established.The tooth profile curve equations were deduced based on the principle of spherical involute formation and the principle of gear generation machining.The gear parametric model was established by CATIA and Matlab,and finite element model of spiral bevel gears was established to the tooth surface contact stress and the tooth root bending stress are calculat ed.(2)Bearing capacity calculation and finite element contact analysis based on gear standard is studied.The tooth contact strength of the spiral bevel gear and the bending strength of the tooth root are calculated respectively according to the ISO 10300(2014)standard and the AGMA 2003-B97 standard.The difference between the two kinds of strength calculation standards is compared.The definition method,the value of the correction coefficient and the influence on the tooth strength are analyzed in the two standards,the influence of design parameters such as transmission ratio,modulus and helix angle on the bearing capacity of gear is discussed.The results show that there are great differences in the strength calculation results under the two standards.The finite element contact analysis of the spiral bevel gear is carried out to calculate the contact stress of the tooth surface and the bending stress of the tooth root,and the calculation results are compared with the gear standards.The finite elem ent analysis is close to the ISO standard calculation result.(3)The method of measuring the tooth root bending stress of spiral bevel gears is studied.According to the spiral bevel gear bearing capacity and experimental requirements,the design of tooth root bending stress test plan and test system are carried out,According to the principle of the tooth root bending stress test,the strain gauges are pasted on the tooth of the convex surface in the spiral bevel gear,the bending stress of the root is tested based on the NI collection system and the Labview software platform.(4)The test results of the root bending stress are analyzed.The time domain average method is applied to deal with the measured stress and strain datum,he test results are compared with two methods aboved.The results show that the experimental values are larger than those of gear standards and finite element calculations.The stress numerical results under the different friction coefficient calculated by finite element analysis is used to build the objective function,and the friction coefficient of tooth surface under dry friction condition is calculated by genetic algorithm.