Research On Key Technology Of A New Large-size Involute Artifact

With the rapid development of shipbuilding,mining,wind power and oil transportation,the application of large gears,a key component of large sets of equipment,is in increasing demand and the requirements for their performance and quality are becoming higher and higher.Measurement is the most direct and effective means of ensuring the quality of large gears.The quality of manufactured gears is controlled by a gear measuring instrument.The accuracy of the profile measurement by such an instrument is evaluated using an involute artifact.The artifact is difficult to manufacture gears with high accuracy because the involute is a complicated geometrical form.Gear involute artifacts are the benchmark for involute gear traceability.As large gear involute profile is difficult to process,and even more difficult to measure,making the traceability for large gears a constant challenge.In order to solve the problem of the traceability of large size involute,this project"Research on key technology of a new large-size involute artifact"takes a different approach by replacing the involute tooth surface with a circular column surface and developing a new large-size involute artifact–the double-axis arc-shaped large-size involute artifact,which provides theoretical support for the establishment of large size involute traceability system,value traceability and expansion of gear involute standard.In this thesis,a principle error model is first developed for a double-axis arc-shaped large-size involute artifact.The principle error model describes the deviation between the circular arc and the theoretical involute.When the arc position is chosen appropriately,the arc can be used as a virtual involute by compensating for the principle error.The mechanism of action of different error sources in the measurement of cylindrical surfaces by gear measuring instruments is then analyzed,providing a solid theoretical basis for the design of the mechanical structure of the new large-size involute artifact.Based on the measurement principle of the double-axis arc-shaped large-size involute artifact,a design method is proposed,a double-axis arc-shaped large-size involute artifact is developed,and a method for calibrating the gear measurement centre is proposed for the artifact.The mechanical structure of the artifact is further optimized using ANSYS Workbench,based on the design principles of deformation resistance and lightness of the large gear involute artifact.The influence of the deformation of the artifact in the radius of the inspection arc and the deformation of the artifact in the centre distance direction on the measurement accuracy of the artifact is analyzed.The topology was optimized for the frame and the counterweight frame of the artifact.The mass of the artifact was reduced by approximately 25.7%after the topology optimization and the deformation resistance of the artifact remained unchanged.Finally,the experimental study of the double-axis arc-shaped large-size involute artifact was carried out,mainly including:（1）The high-precision assembly of the artifact plate was completed,and the parallelism of the artifact plate in the two directions of the measuring axis and the centering axis was ensured through the assembly.（2）In Harbin Ultra Precision Equipment Engineering Technology Center Co.,Ltd and National Institute of Metrology,China,high-precision verification was carried out on the artifact.The maximum error of the two verification results was less than2.6μm,and the verification results were credible.（3）The measurement experiments of the artifact were carried out on the Klingenberg P100 gear measuring centre at the National Institute of Metrology,China and the experimental data were processed and analyzed to obtain the three performance indicators f _FK,f _VB and f _NC used by the artifact plate to evaluate the gear measuring instrument.（4）The measurement uncertainty error sources of the artifact were analyzed,and the uncertainties when the artifact calibrated the instrument were given.This thesis proposed a double-axis arc-shaped large-size involute artifact design method and develops a new large size involute artifact.The developed the double-axis arc-shaped large-size involute artifact has the advantages of small shape error,low price and traceability of accuracy.Although the use of circular arcs instead of involutes is not a new method,the use of precision-calibrated narrow cylinder to produce large gear involute artifact is a unique method for evaluating large involute gears.