| Spiral bevel gears are one of the important parts in mechanical transmission.These gears have excellent characteristics such as high strength,low noise and good transmission performance in the transmission process,so they are widely used in the intersecting shaft transmission in the space where high speed and large load are required.Spiral bevel gear tooth structure is complex,manual modeling is difficult and modeling efficiency is low.Therefore,it is important to study the accurate modeling method of spiral bevel gears and realize its fast modeling to improve the modeling efficiency and ensure the quality of spiral bevel gears.In this thesis,the spiral bevel gear modeling method and tooth contact containing mounting errors are investigated by combining these tools with Matlab,the 3D modeling software UG,UG’s own secondary development modules Open GRIP,and ANSYS Workbench,using the local synthesis method and the meshing principle as the theoretical basis.The main research elements of the thesis are:(1)The tooth equations of the large wheel and small wheel are derived by using the principle of meshing,combined with the coordinate transformation theory.The machining parameters of the large wheel are obtained from the Gleason calculation card,by the local synthesis method,the second-order contact parameters are preset and the small wheel machining parameters can be derived.(2)According to the tooth contact analysis,the program of tooth contact analysis was written in Matlab,and the suitable transmission error curve and tooth contact imprint were obtained by continuously adjusting the machining parameters.Combined with the tooth surface equation,the rotation projection principle was used to solve the discrete points on the tooth surface using Matlab programming,which provides the basis for the UG secondary development later.(3)Using UG/Open GRIP as the secondary development tool,the discrete points were imported into UG,and the program that can read the discrete points to automatically generate the large and small wheels of spiral bevel gears was written by Open GRIP,and on this basis,the program that can automatically assemble the large and small wheels of spiral bevel gears was completed,and they were automatically assembled into gear pairs by the program.(4)The finite element method was applied,and the finite element analysis of the gear pair was carried out based on ANSYS Workbench.The spiral bevel gear model was simplified with UG,and five teeth were taken from each of the large and small wheels,and the gear pair was assembled and imported into Workbench for finite element analysis.The gear model without installation errors was first analyzed statically,and contrasted with the later model with installation errors.The gear model containing installation errors was well established with UG,and the gear was analyzed for installation errors.During machining and installation,four types of errors exist in spiral bevel gears: large wheel axial installation distance error,small wheel axial installation distance error,shaft pitch error and shaft intersection angle error,and the effects of the four types of installation errors on the contact characteristics and changes in stress in tooth contact were analyzed in turn.Machining tests were conducted on a conventional Gleason gear milling machine,and the correctness of the designed machining parameters was verified by machining tests,and a spiral bevel gear pair was machined,and use the roll inspection machine to check whether the gear sub contact area position is reasonable. |
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