Straight face gear transmission is a transmission in which straight cylindrical gears mesh with face gears, mainly used to transmit motion between intersecting shafts. Straight tooth surface gears can be considered as a special type of bevel gears. Straight tooth surface gear transmission has many advantages, such as small volume, large transmission ratio (generally greater than 3.5), easy assembly and adjustment, and low vibration and noise. It has unparalleled advantages in the aerospace field. At present, the machining and manufacturing method of spur gear generally adopts cutting processing. The current machining methods have the disadvantages of low machining efficiency and low material utilization. The most important thing is that traditional machining methods can cut the metal fiber flow line, resulting in a reduction in the bending stress at the root of the straight tooth surface gear. Based on this, the method of hot rolling is used to make the teeth of spur gears, leaving a finishing cutting allowance.
Hot rolling is an advanced manufacturing technology for plastic forming workpiece through mold feed motion at a certain temperature, which can effectively improve the microstructure and surface quality of the workpiece. At present, great progress has been made in the research of rolling cylindrical gears at home and abroad. Zhao Jun took spiral bevel gears as the research object and analyzed the rolling forming process of spiral bevel gears. Yan Ke proposed a new rolling method for spur gear, the conical rolling wheel gear rolling process, and designed an experimental device to verify its feasibility. Domestic scholars such as Zhu Xiaoxing have theoretically solved and analyzed the relative sliding between tooth profiles by using the trapezoidal area approximation instead of the long and high tooth profile area of the rolled piece, verifying the effect of the relative sliding between tooth profiles on the metal flow direction of the tooth profile. Qiao Shuo et al. used the finite element software DEFORM-3D to simulate and analyze the metal flow law and equivalent strain field of cylindrical helical gears during the rolling process. Zhang Shaolin conducted numerical simulation research on the rolling process of straight bevel gears. Zhang Yuming and others have studied the service life of gear rolling wheels and optimized the forming process parameters. Tang Hongyan conducted numerical simulation on the processing parameters of spiral bevel gears, proving the feasibility of hot rolling of spiral bevel gears, and designed the experimental device.
Currently, the near net rolling forming technology is widely used in cylindrical gears, threads, involute splines, etc. The research on the rolling process of spiral bevel gears is also ongoing, but the rolling of spur gear has not been reported. By establishing a mathematical model for hot rolling spur gears and conducting orthogonal experiments on the hot rolling process of spur gears, the most reasonable process parameters are selected to lay the foundation for subsequent experimental research.