Under extremely complex conditions, the bearing capacity, service life, safety and meshing tooth surface contact behavior of high-performance gear transmission are directly related to the macro and micro morphology and microstructure distribution of gear matrix and tooth surface. Therefore, the design requirement of controllable micro morphology and texture of gear tooth surface puts forward new problems for efficient and green manufacturing; The continuously improved performance of gear materials forms a more acute contradiction with the higher and higher requirements of machining accuracy, forming stability and machining efficiency; The generation of high-precision complex tooth surface and the inheritance and suppression of geometric error are very different from the traditional generation envelope machining in principle. In short, how to realize the high-precision and controllable high-efficiency manufacturing of gear macro and micro integration is a key scientific problem to be solved in high-performance gear transmission. The mapping relationship between machining process parameters of high-strength gear materials, tool parameters, complex dynamic and static response of machine tools, forming accuracy and tooth surface morphology is diverse. The establishment of machining interface behavior model is very complex. The manufacturing of high-precision and high stability of high-performance gears is facing great scientific challenges.
In order to improve the performance of gears, a lot of in-depth research has been carried out on gear materials, tooth profile design and tooth surface material performance improvement after tooth surface forming at home and abroad, and good results have been achieved. In contrast, there is less research on the error, inheritance and coupling of error in the process of tooth surface forming and manufacturing. The gear forming process mainly includes tooth blank forming, tooth surface rough forming, tooth surface modification and tooth surface precision forming. The error of each link must be strictly controlled in high-performance gear manufacturing, and the error of the previous process will not only be inherited to the subsequent process, It will also affect the modification effect of tooth surface. This project focuses on one of the most extensive process links in gear processing and its error formation mechanism.
Gear hobbing is a very efficient and typical tooth making method. It is widely used in semi finishing of hard tooth surface and precision forming of soft tooth surface (especially large gears that cannot be ground), but the structure of machine tool, tool structure and tooth surface forming mechanism are very complex. In the process of gear hobbing, there are many error sources, many error transmission paths, complex mapping relationship and great difficulty in error control. A lot of manpower and material resources have been invested in the research and development of precision hobs and gear hobbing machines at home and abroad. Now foreign gear hobbing machines can stably process gears with grade 5 precision, and domestic CNC precision gear hobbing machines can process gears with grade 6 precision (some deviation items are Grade 6, some are lower than grade 6), The workpiece tooth surface error of gear hobbing processing has a correlation with the structural parameters of the tool, the blade error, the stiffness of the tool and workpiece system, the accuracy and dynamic characteristics of the machine tool. So far, the literature on this correlation is very rich, but most of them have only carried out qualitative analysis, and a few of them have quantitative description. Among them, there are many studies on the mapping of single error to the tooth surface, There are few studies on the influence of genetic and coupling of multivariate errors in the process of tooth surface forming and manufacturing on the accuracy of tooth surface forming.
There are many factors affecting the forming accuracy of tooth surface, which mainly depend on the gear machining mechanism, machine tool accuracy, gear cutter accuracy, process method, gear blank accuracy and material, ambient temperature, etc. the gear machine tool accuracy, gear cutter accuracy and gear blank accuracy will be mapped to the gear accuracy in a certain functional relationship, which is related to the machining mechanism, process method The gear blank material is related to the ambient temperature. At present, the accuracy of precision gears produced in China is lower than the international level by 1-2. To further improve the forming accuracy of gears, it is necessary to study the mapping relationship between multi-source geometric errors and gear comprehensive errors, and explore the efficient forming mechanism under the coupling action of cutting force strain heat fluid and other fields in high-precision tooth surface generation, The accurate traceability mechanism and error suppression strategy of tooth surface forming error are established to provide basic theory for gear precision forming.