Research On Error Mapping And Mechanism Of Error Generation For Large-sized Gear Profile Grinding Machine

Large-sized and high-precision gears,especially those whose diameters are larger than 3 m,are extremely important basic components for high-end equipment,such as large surface warship,high power generator and construction machinery.However,due to the precision evolution mechanism of large-sized gear grinding machine are not well understood,and error compensation methods cannot meet the demand,designers generally design large-sized gear grinding machine with traditional safety factors or empirical method.This method seriously restrict the improvement of the precision of transmission,the load capacity and the service life of the large-sized gears.In 2014,China first developed a large-sized CNC gear profile gear grinding machine,however,the machining precision and precision stability of this gear grinding machine are still left far behind that of the same type gear grinding machine of foreign advanced gear grinding machine.Thus,the gear grinding machine tools developed by China can not meet the demand of gear processing in key industries.Therefore,it is of great essential to develop the research of precision evolution mechanism of large-sized gear grinding machine.This paper mainly studied two problems: the error mapping mechanism form machine tool errors to gear processing errors,the multiple errors generation principles of grinding machine.The specific contents of the article are as follows:1 Research on error mapping mechanism form machine tool errors to gear processing errors.By studying the gear profile grinding principle,a computing method was proposed to solve the shape of the wheel according to gear parameters and processing parameters.We established a error model of large-sized gear grinding machine containing machine tool assembly errors,motion errors and spindle servo errors.Also,a model for calculating gear errors was also proposed.At last,for gear grinding example,we calculated the error mapping mechanism using the above models in MATLAB software.2 Research on the deformation of the large-sized gear grinding machine under the effect of the Gravity and the modal deformation of the large-sized gear grinding machine.In order to analyze the structure characteristic of large-sized gear grinding machine,we carried out 3-dimensional modeling and finite element analysis of machine tool using SOLIWORKS and ANSYS workbench software.The deformation results canbe used for improving the dynamic/static stiffness of machine tool and optimizing the structure of machine tool.3 Research on the thermal error of motorised spindle in large-sized gear grinding machine.The thermal deformation of the mororised spindle n large-sized gear grinding machine under different rotational speeds were studied by means of experimental method.The thermal error model of the spindle is established by studying the multivariate relationship between the temperature changes of the selected measurement points and the thermal deformation of the motorised spindle.Experiments results show that the models has the ability to predict the thermal error of the motorised spindle under different rotational speeds.4 Research on the influence of motorized spindle vibration on processing precision and precision stability.As large-sized gear grinding machines developed by China generally perform poorly in terms of processing precision and precision stability,this paper established the dynamic model of gear profile grinding process.The critical stability conditions of gear profile grinding process are analyzed in time-domain and frequency-domain.Through the fine gear grinding experiments and the signal processing,the time and frequency domain characteristics of the gear grinding process are obtained.