Grinding plunge shaving cutter for diagonal modified helical gears

Abstract:

An approach based on CNC grinding machine of plunge shaving cutter for diagonal modified helical gear was proposed to reduce grinding errors and improve meshing performance. Firstly, the corresponding plunge shaving cutter surfaces for the diagonal modified helical pinion was established based on gear theory. Secondly, a free-form flank topographic correction method based on Y7432 grinding machine, with flat wheel translated along normal sections of invented rack-cutter, was established according to principle of rack-cutter generating involute pinion. Thirdly, an error correction model based on a sensitivity analysis was determined, each axis of the machine was formulated as a six-degree polynomial and a disturbed polynomial coefficient on the topographic flank errors was developed by estimating whether the wheel contacted with the pinion. Finally, using minimum squared error as the objective function to get the smallest grind errors, the PSO optimization algorithm was introduced to solve equations of the corrections, and the polynomial coefficients were ascertained. The result shows that the methods can effectively reduce the grinding error, and the topologically modified tooth for plunge cutter can be represented by sum of longitudinal and diagonal deviations surface. The slight variations in pressure angle and generating angle and helix angle can attain some specific diagonal modified tooth respectively, besides, the diagonal modified helical gear with big size and helix angle can then be efficiently ground by slightly adjusting three-axis movement with a smaller translating flat wheel.