Aiming at the most typical gear hobbing process of gear forming, focus on the multivariate mapping relationship between gear accuracy and gear hobbing process and equipment:
① Mapping law between gear hobbing system error and gear geometric accuracy
Aiming at the typical gear hobbing method, the mapping relationship between gear hobbing system and workpiece gear error is studied without considering tool error and machining system deformation. The systematic error of gear hobbing includes installation error and motion error.
② Influence of gear hobbing principle error on gear geometric accuracy
The ideal gear hobbing processing is that the hob makes rolling meshing with the gear, continuously cuts the gear, and finally processes the ideal gear; In the actual machining process, the gear hobbing cutter does not cut the gear workpiece continuously, but cuts intermittently, which leads to the sawtooth profile error caused by intermittent cutting in the gear hobbing process. The error model of gear hobbing principle is established, the gear hobbing principle is analyzed, and the mapping relationship between gear hobbing principle error and gear machining accuracy is put forward.
③ Influence law of gear machining system vibration on gear geometric accuracy
In the process of tooth surface forming, workpiece, cutting tool, machine tool and tooling will vibrate due to the existence of cutting force. The low-frequency vibration of the machine tool will produce the tooth profile error of the workpiece gear, and the high-frequency vibration will affect the surface roughness of the workpiece tooth surface and the generation of microcracks. Aiming at the typical gear hobbing machine, the vibration model of gear hobbing machine is established, the dynamic characteristics of gear hobbing machine are analyzed, the method to reduce the vibration of machine tool is found, and the quantitative evaluation method of tooth profile geometric error and tooth surface morphology caused by vibration is put forward.
④ Mapping Law of tool geometric error to gear geometric accuracy
The error of the gear cutter itself will also be mapped to the workpiece gear in the machining process. There are tooth profile error and tooth direction error in the cutter edge, and there is helix error in the arrangement of the gear hobbing cutter edge. When machining gears by forming method, the mapping relationship between tool error and workpiece gear error is more intuitive; When generating envelope method is used to process gear, taking gear hobbing as the object, the mapping relationship between geometric error of hob and geometric error of workpiece gear is established.