Research On Design And Manufaceturing Technology With The Arc Tooth Face Gear Transmission

The arc tooth face gear drive is a new transmission type with automatic adjustment and positioning function.Compared with straight tooth gear and helical gear,arc tooth surface gear not only owns high bearing capacity but also has the merits of simple manufacturing process and low cost.The gear processing machines for the arc tooth face gear can just be conventional Gleason cutter and domestic existing CNC machining center or CNC gear machine.And the design and manufacturing process of engineering-oriented aviation gear transmission device can already been finished in a short period of time.Besides,due to the military use of face gear transmission technology,arc tooth surface gear transmission technology must be developed independently and domestically.In this dissertation,basic meshing theory,working principle,tooth surface as well as tooth width design of arc tooth surface gear are thoroughly discussed.Meshing and bearing characteristics analysis,optimizing modification technology,modification surface cutting design,milling process,hobbing test and so on are also conducted for arc tooth surface gear.The main contributions of this dissertation can be summarized as follows:1.An the generating method in processing the arc tooth face-gear pairs is investigated.The generating method is adopted to process an arc tooth face-gear and an imaginary shape gear simultaneously conjugated meshing with an arc tooth cylindrical gear and an arc tooth face-gear.It guarantes accurate meshing of the arc tooth surface pair.A cutter head model designed with certain cutter inclination,the normal-section equations of the cutter head with linear and involute are established.The tooth surface equation of the imaginary shape gear shaped rack is deduced from spatial coordinate transformation.2.The surface models of the arc tooth face-gear pairs are proposed.The models of the working tooth surface and the tooth root fillet are derived from meshing principle,differential geometry and spatial coordinate transformation.The non-undercutting and avoiding pointing conditions established,the tooth width for the arc tooth face-gear is acquired.The precise 3D model was built for the arc tooth face-gear by the c alculation example.It ensures the precision of the generating method in processing the arc tooth face-gear pair.The high precision models of the arc tooth surface pair are realized based on he numerical tooth surface.The linear profile cutter substitutes involute profile cutters processing the arc tooth face-gear pairs to simplify the processing.3.The models of tooth contact analysis(TCA)and load tooth contact analysis(LTCA)is established considering the assemble errors.Comparative studies are show that the geometric transmission error curve for the arc tooth face-gear pairs is middle-convex parabola.It can absorb the deviation produced by various installation error,reduce the cycle point impact.Under work load conditions,using the linear profile cutter processing the arc tooth face-gear pair has serious edge contact,the larger load transmission error amplitude causing vibration and noise.4.The modification optimization on the arc tooth face-gear is researched.To improve the transmission quality and bearing capacity,the modification compensation for the arc tooth face-gear pair is made.The radius difference of convex and concave meshing tooth line is calculated by the preset contact length to achieve the modification in tooth line direction.The cutter radius selected based on LTCA.For increasing material modification optimization of the arc tooth face-gear profile,two paraboli concave approaching involute profile tooth surface is adopted.The weight coefficient of Genetic Algorithm(GA)for multi-objective optimization is adopted to optimize the modification factors by minimizing amplitude of the geometric transmission error in meshing into-out cycle point and load transmission error.The modification surface is added by calculating error surface and the arc tooth face-gear theoretical surface.Design examples verifies that the simple linear profile cutter instead of involute profile cutters processing the arc tooth face-gear is feasible.Good dynamic meshing and bearing performances are obtained by the modification.5.A general six-axis computer numerical control(CNC)machine is adopted to process the surface and modification surface.Adjustment parameters of the cutter-tilt machine are converted to that of a common multi-axis NC machine based on space coordinate transform.The models for the six-axis NC machine generating the arc tooth face-gear pairs is established.Trimming CNC machine each axis machining modification surface,the tooth surface deviation model for the arc tooth face-gear modification surface is built baced on sensitivity analysis of each axis in the NC machine.With the least square sum of the tooth surface error being the optimization objective,the each axis trimming parameters are solved by PSO.The axes parameters for processing modification tooth surface are obtained by the parameters superposition with each axis coefficients for cutting arc tooth face-gear theoretical surface.A numerically controlled machine model for the machining arc tooth face-gear modification surface is established.The error model of cutting modification tooth surface is deduced,to get the error surface of the target modification tooth surface and.Simulation results demonstrate that rimming CNC machine each axis machining modification surface is Effectively.The method guarantes the cutting accuracy.6.Experimental results are presented to verify generating method,tooth surface design,modification theory and meshing performance analysis for the arc tooth face-gear pairs.Machining and meshing testing are completed.Experimental results show good consistency with the theoretical analysis.It verifies the feasibility of accurate meshing the arc tooth face-gear of the linear profile cutter processing with the arc tooth cylindrical gear.