Research On Design And Manufacturing Technology Of Curvic Coupling

Curvic coupling has the advantages of high centering accuracy and strong bearing capacity due to its special tooth shape.It was mainly used in the connection between the parts of the rotor system of modern aero-engine.With the continuous improvement of the aero-engine performance,the requirements for the manufacturing accuracy of curvic coupling were also improved accordingly.In this paper,the parameters of tooth blank and the calculation method of grinding/cutting machining parameters,mathematical modeling of tooth surface,contact analysis of tooth surface and correction of tooth shape error are studied.A set of design and machining technology of curvic coupling is established,which can realize the digital closed-loop manufacturing of curvic coupling,thus improving the machining precision and machining efficiency of curvic coupling.The main research work of the thesis is summarized as follows:1.According to the traditional strength checking theory,the geometric parameters of end-face arc tooth coupling,such as diameter,module,tooth number,tooth top height and tooth root height,are calculated by the given torque.Based on the machining principle of curvic coupling,the calculation method of adjusting parameters and cutting tool parameters of grinding/cutting machine tool is established,the adjustment parameters of the machine tool and the tool parameters for determining the grinding edge shape of the grinding wheel are calculated.2.Based on the machining principle of curvic coupling,the generating surface equation and tooth surface equation of grinding wheel are established.The space coordinates and normal vectors of the discrete points on the tooth surface are calculated by discretization.Based on the position relationship between concave gear and convex gear,the tooth contact analysis method of end surface arc gear coupling is established,the contact state of the tooth surface is judged by the space coordinates of the corresponding points of the concave tooth surface and the convex tooth surface and the distance between them.3.Based on the relationship between the unit increment of the machine tool adjustment parameters and the grinding wheel parameters and the tooth shape variation,the error sensitive Matrix is established,and the equations of tooth shape error identification and compensation are established,using the Tikhonov regularization+L curve method to solve the system of linear equations,the adjustment parameters of the machine tool and the parameters of the grinding wheel for correcting the profile error can be obtained.The correctness of the tooth profile error correction method is verified by an example.4.Using Visual Basic and Fortran programming software,a complete set of software a complete set of software is developed for the design,analysis,calculation of machining parameters and tooth shape error correction of curvic coupling.The digital closed-loop manufacturing system of curvic coupling is constructed by combining numerical control grinding machine and gear measuring center to realize the digitization and intelligence of curvic coupling manufacturing process.5.On the basis of H350GA NC bevel gear grinding machine and L65G high precision gear measuring center,the grinding tooth machining,tooth shape error correction and coloring style inspection of the test workpiece of curvic coupling are completed.The maximum tooth shape error of concave teeth was corrected from 14.3μm to 3μm,and the maximum tooth shape error of convex teeth was corrected from 12.8μm to 1.4μm.The experimental results verify the correctness of the design,analysis,machining parameter calculation,tooth shape error correction method and digital closed-loop manufacturing technology of curvic coupling.