The Research On Error Evaluation Of Critical Conjugate Of Toroidal Drive

Toroidal drive is a new type of transmission device,which combines the advantages of planetary transmission and worm drive,has the advantages of large carrying capacity,large transmission ratio and high transmission efficiency.However,due to Toroidal drive through the space multiple conjugate transfer movement and power,the key engagement parts of the design and processing difficulties in the processing and assembly process prone to error.In the aspect of error evaluation,there is no uniform evaluation method,lack of precision evaluation system,which seriously constrains the wide application of this kind of organization.Therefore,it is of great significance to establish the accuracy specification of the key parts of Toroidal drive.The main research contents in this study:(1)Based on the principle of multiple conjugation and spatial meshing theory,the meshing equation,tooth equation,contact line equation and helix equation of Toroidal drive are deduced.The three-dimensional accurate model of the mechanism was established by means of contact line,and the accuracy of the model is compared with other methods by means of ADAMS motion simulation.(2)According to the method and accuracy system of gear transmission error assessment,the formulas for calculating the permissible value of tooth profile error and the allowable value of tooth pitch error are deduced.The mathematical model of the tooth profile error and the pitch error of the center worm and the tooth profile and pitch error of the inner ring gear are established,and the accuracy of the planetary worm transmission mechanism is established.(3)The estimation parameters of linear model and parabola model are solved by the least square method and the cumulative method respectively.The cumulative error of the tooth profile is separated from the total error of the tooth profile by the cumulative method,and the estimation accuracy of the cumulative method and the least squares method in the error data processing is analyzed by case analysis.(4)The measurement of the contact line of the central worm and the planetary roller contact line,the inner gear ring and the roller of the planet wheel is measured by three coordinate measuring machine.The error data and the allowable value are compared with the allowable values of the tooth profile error and pitch error obtained by the calculation method.The accuracy level of the center worm and the ring gear is determined.The Research show that the three-dimensional model established by the method of precision modeling is more accurate than other methods.In the data processing,the estimation precision of the accumulative method is higher than that of the least square method,and the error precision of the part can be determined by comparing the error result with the allowable value.It lays the foundation for the establishment of the perfect system of multiple conjugate transmission mechanism.