Study On The Form Grinding And Grinding Wheel Dressing Technology Of Screw Rotors

The high-precision processing technology of complicated cross section screw rotors hasbecome a bottleneck to the rapid development of refrigerant compressors、industrial pumpsand air compressors,however,wheel dressing as the core technology of form grinding wheelswill directly affect the profile accuracy and surface quality.of the screw rotors.For the discrete points of teeth profiles,a mathematical model about the processing wasdeveloped based on the principles of gear connection,the contact line equation between thegrinding wheel and the rotor was deduced under the tangent condition,then converse thecoordinate and the profile of grinding wheel was calculated.The key to calculate the profile of grinding wheel is to solve the contact line equationwhich involves slope calculation and transcendental equation solution.Cubic spline function、chasing method and least square method were used together to calculate the profile ofgrinding wheel successfully.In order to meet the machining accuracy of NC machine tools,theprofile of grinding wheel which as a tabulated curve was faired、fitted and interpolatedthrough local smoothing method、cubic spline function and equal interval method,a betterfitting effect was got at last.A wheel dressing plan was designed based on grinding wheel dresser’s construction andthe calculation result.The dressing routing and the choice of processing parameters wasanalyzed in detail.Then NC program on wheel dressing was edited with ‘R’ parametersfinally.Tn order to gain broader and more convenient applications,a software about screw rotorform grinding based on MATLAB GUIDE was designed which can be used to calculate theprofile of grinding wheel and generate programs Automatically.