Research On Method Of Forming Involute Profile Of Harmonic Gear And Grinding Wheel Dressing Device

Harmonic gear transmission has the advantages of small indexing error,high transmission ratio,small volume and smooth transmission compared to cylindrical gear transmission.It is widely used in industrial robots,precision mechanical transmission,aerospace and other fields.Since the module of the harmonic gear is small,it is generally 0.15 mm~0.5 mm,and high-precision machining of the tooth profile is difficult.Therefore,manufacture of high-precision harmonic reducer has become a major obstacle to the development of advanced industrial robots in China.The involute tooth profile is a widely used tooth profile for harmonic gears.Therefore,improving the machining accuracy of the involute harmonic gear with small modulus has important research significance for improving the precision of harmonic gear transmission.In this dissertation,under the support of the National Natural Science Foundation of China(No.U1508211),the method of forming the tooth profile of the harmonic gear and the grinding wheel dressing device are studied.Based on the principle that the space rotates around a coordinate axis to generate a rotationary body with a hyperbolic generatrix,a method for obtaining a high-precision hyperbolic profiled grinding wheel by using a single degree of freedom straight line trimming motion is proposed,which is used for involute harmonic external gear precision forming processing.A mathematical model was established between the attitude parameters of the straight dressing motion and the hyperbola that best approximated the involute curve.Based on the principle of fitting the involute curve by the hyperbola formed by the space straight line,a symmetrical double tapered surface forming wheel was proposed.Trimming method;By adjusting the yaw angle of the diamond pen and the eccentricity between the dressing plane and the wheel assembly axis,the profile of the hyperbola forming grinding wheel is optimized to obtain the adjustment parameters with the best approximation of the involute profile;A symmetry double-cone shaped forming wheel dressing device includes a high-accuracy 180°flip positioning device,a high-precision diamond pen wheel dresser and a high-precision adjustable connection device to ensure symmetrical accuracy of the double-cone surface,The straight line dressing accuracy of the diamond pen and the adjustment precision of the diamond pen deflection angle were simulated based on NX 10.0 motion simulation software.The simulation results were basically consistent with the theoretical calculation results,thus verifying the mathematical model’s accuracy.Through theoretical analysis and simulation verification of this dissertation,the feasibility and effectiveness of using a hyperbolic shaped grinding wheel obtained by straight dressing motion to process a small modulus involute tooth profile harmonic gear are pointed out,and it It plays an important role in the development of high-precision harmonic gear reducer.