Research On Continuous Generating Grinding Method Of Face Gear Based On Cylindrical Gear Worm Grinding Machine

Face gears are gradually replacing bevel gears as the core part of the transmission systems in the new helicopter.Face gear drive breaks the limitation of performance parameters such as size,load and speed,which has the advantages of stable transmission ratio,high coincidence,and insensitive to installation errors.However,China cannot apply face gears in engineering due to the lack of face gear precision grinding technology.The main problem is that the face gear worm grinding wheel is special-shaped.The solution process is cumbersome and limited by singular points when modeling the grinding worm.Moreover,the worm dressing and the gear grinding motion are complex,and a complex machine tool structure is required,which makes it difficult to control the precision of the machine tool.As a result,the grinding accuracy of the tooth surface is difficult to meet the requirements.Therefore,in this paper,aiming at the precision generating grinding technology of face gears,the modeling of face gear worm grinding wheel and the method of grinding face gear on cylindrical gear worm grinding machine are studied.The main research contents are as follows:(1)The mathematical model of the crown worm wheel for face gear grinding is established.Firstly,the working surface and the fillet surface equations of the face gear are given,the minimum inner radius and the maximum outer radius of the face gear are analyzed,and the discrete points of the tooth surface are calculated by an example.Secondly,the evolution calculation method of the crown worm for face gear grinding is proposed,and the profile equation of the crown worm is deduced based on the evolution method.Finally,the discrete points of the crown worm profile are calculated by an example,and the deviation of the evolution method and the traditional envelope method is analyzed.(2)The forming dressing method of the crown worm on the cylindrical gear worm grinding machine is studied.Firstly,the kinematic characteristics of the forming dressing for the crown worm are analyzed.Then a forming dressing method of the crown worm based on virtual center distance principle is proposed.The deflection of the dressing wheel is replaced by the deflection of the worm,and the dressing stroke of the crown worm is completed by the linkage of the A1,Y1,Z1 and B1 axis.Finally,the correctness and feasibility of the method are verified by numerical simulation and machining simulation respectively.(3)The method of grinding face gear on the cylindrical gear worm grinding machine is studied.Firstly,the motion principle of grinding face gear by worm is analyzed.The radial feed path for grinding face gear on the cylindrical gear worm grinding machine is planned.Then the correctness of the grinding trajectory and the feasibility on the gear grinding machine are verified by numerical simulation and machining simulation respectively.In addition,aiming at the unique tool alignment problem in the worm grinding of face gear,the tooth surface error caused by the misalignment of the tool during grinding is analyzed,which provides a reference for the reverse adjustment of tooth surface error in face gear grinding.(4)The hardware transformation and software development are carried out based on the YS7232 gear worm grinding machine.On the one hand,based on the researched worm dressing and gear grinding method,a reformation plan for the hardware structure of YS7232 worm grinding wheel is proposed.On the other hand,the HMI interface of face gear grinding is developed based on SINUMERIK 840 Dsl,which laid the foundation for face gear grinding on YS7232.