Gear is one of the important transmission elements of machine system. The conventional cutting manufacture methods of gears, including gear hobbing, gear shaping, gear milling, gear wire cutting, ect. As to the forming processes of manufacture methods including forging, die-casting, injection molding and sintered powder-metal gears. Among them, the sintered powder-metal gear not only has great advantages of material-saving, labor-saving, cost reduction and suitable for mass production, but also has good mechanical properties for the gears. It has been widely used in automobiles, electrical machines and household appliances.
In the powder-metal gear manufacturing, due to the influences of forming and sintering conditions, the unstable defect on the green compact parts’ dimensions, results in the gear profile geometric errors. Consequently, the gear transmission errors, vibration and noise occur during the gear pair meshing. Therefore, it is most important to improve the gear manufacture precision to reduce the gear transmission errors, vibration and noise. To obtain a high precision gear, the control of gear dimensions and variations is important. Therefore, design and manufacture of a good shape of forming die decide the products’ quality.
This study refers to the conditions of practical powder-metallurgy manufacture process, and proceeds to experiments and gear precision measurements as well as investigation on the relationship of the powdwer-metallurgy parameters and gear precision. Furthermore, the mathematical model for spur gear is developed based on the theory of gearing, and sensitivity analyses of gear parameters and gear surface deviations are performced. Then, comparison with the results of experiments and computer simulations, in attempt to evaluate an ideal amendment on the parameters of a forming die. It enables a suitable compensation on gear surface deviations which resulted from the powder-metallurgy process, and attains a high precision powder-metallurgy gear.
This study refers to the conditions of practical powder-metallurgy manufacture process, and proceeds to experiments and gear precision measurements as well as investigation on the relationship of the powdwer-metallurgy parameters and gear precision. Furthermore, the mathematical model for spur gear is developed based on the theory of gearing, and sensitivity analyses of gear parameters and gear surface deviations are performced. Then, comparison with the results of experiments and computer simulations, in attempt to evaluate an ideal amendment on the parameters of a forming die. It enables a suitable compensation on gear surface deviations which resulted from the powder-metallurgy process, and attains a high precision powder-metallurgy gear.
