Research On Hypoid Gear Lapping Process And Improving The Lapping Quality Of Drive Axle For Automobile

The constant-depth tooth hypoid gear pair,main transmission part of rear axle main driving of automobile transmission system,serves to reduce the speed,increase the torque and change the direction of motion.Compared with other hypoid gears,the constant-depth tooth hypoid gear occupies better NVH performance and higher processing efficiency.In recent years,it has been widely applied to automotive field in China.The constant-depth tooth bevel gear lapping is the final procedure of gear machining and its processing quality is a key factor affecting the gear transmission noise.Meanwhile,the consistency of gear lapping tooth surface contact imprints,tooth-face roughness,and the transmission error of matching gears also exert significant effect on the gear transmission noise.In order to improve the processing quality of rear axle constant-depth tooth bevel gear of Front-engine Rear-drive automobile and then better the NVH performance of rear axle,rear axle constant-depth tooth bevel gear is analyzed and studied in the present paper.The results are summarized as follows.(1)After an investigation into the processing quality of the constant-depth tooth bevel gear lapping,problems arise.It can be found from the experiment that the processing quality of the constant-depth tooth bevel gear lapping(contact area,tooth-face roughness and transmission error)exerts apparent effect on NVH performance.(2)Through modeling the constant-depth tooth bevel gear lapping and analyzing the mechanism of the constant-depth tooth bevel gear lapping,the V/H gear lapping motion controlling model is established.The influences of lapping liquid types and gear lapping parameter on gear lapping quality are analyzed theoretically.Then contact patch and lapping path are designed.(3)An experiment is conducted in order to select and match lapping liquid,decide the size of wear particle and its allocation ratio.The results verify the superiority of new lapping liquid.(4)Orthogonal Experiment is carried out concerning gear lapping equipment parameters torque,speed and gear backlash and then the data is analyzed by least square method.Finally,the new gear lapping parameters are pointed out.(5)Through verifying the optimization scheme of gear lapping and comparing the results before and after the optimization,the author claims the advantages of the consistency of gear lapping contact imprints after optimization.The tooth-face roughness Ra,Rsk and transmission error decrease by 0.4?m,0.6 and 18?rad respectively;the NVH performance is within 65 dB.What's more,the gear lapping quality control standard is built;the using period of lapping liquid and the requirements of fixture accuracy are emphasized;and new classification standard for contact area is also established.The present paper analyzes the influencing factors of constant-depth tooth bevel gear lapping and the optimization of these factors for the purpose of improving the processing quality of gear lapping,solving the problems of meshing noise and peculiar noise in the rear axle,and establishing constant-depth tooth bevel gear lapping optimum technological process.