For a long time, short service life, poor reliability and heavy structure have become the three major problems restricting the development and safe use of China’s gear industry, and forming manufacturing is the main reason for the three problems. There are many factors that affect the gear machining quality. From the perspective of technology and process, there are mainly process design factors, mechanical machining factors such as transmission clearance, stress and thermal deformation, cutting parameter selection, measurement feedback, analysis and calculation and other control factors. In the gear hobbing process, the tooth profile error and tooth direction error can not reach the accuracy standard, which affects the service performance and service life of the gear. Therefore, we must strengthen scientific and technological innovation and break through the core key technology from two aspects: gear hobbing processing technology and gear hobbing manufacturing equipment; Due to the limitations of structure and process, more research is to break through the control method.
The accuracy of gear is divided into motion accuracy, stability accuracy and contact accuracy. The tooth profile, tooth direction error and tooth surface defect produced in gear hobbing directly affect the three accuracy of gear. Gear hobbing is generally used as the previous process of shaving, and its accuracy determines the shaving accuracy and gear quality.
The machining accuracy and efficiency of gear hobbing depend on the accuracy and stiffness of gear hobbing machine to a great extent. At present, Y3150, Y38 and other gear hobbing machines widely used by enterprises can be improved from the aspects of dynamic measurement and adjustment of transmission clearance, improvement of system stiffness (hob, gear steel and machine tool), reasonable control of hobbing amount, so as to reduce mechanical error and improve machining accuracy; Ys3120cnc6, ygs3608cnc6 and other CNC gear hobbing machines are equipped with CNC compensation functions of electronic gearbox and mechanical clearance, which can realize indexing and differential compensation functions, so as to improve transmission accuracy.
In addition, the thermal deformation in gear hobbing will also affect the machining accuracy. Combined with the theoretical calculation of hobbing deformation, dynamic vibration displacement and thermal deformation, the thermal error compensation model of the change of spindle center distance of gear hobbing machine is established to effectively predict and control the thermal deformation and gear machining error of gear hobbing machine, which can improve the machining accuracy and efficiency of gear hobbing.