关键词: 前后缘, 椭圆拟合, 百叶轮, Hertz接触理论, 等弦高误差法

Abstract: Aiming at the structural difficulties of the thin thickness of the leading and trailing edges of the blades and the sharp change of the curvature, the least square method was used to fit the ellipse of the discrete points of the blade section including the leading and trailing edges and part of the blade body. By setting the three error constraints of the average distance, maximum distance and subtraction of slope, the boundary of the leading and trailing edges was identified. The elastic tool flag wheel suitable for the leading and trailing edge polishing was selected, and the polishing model of the flag wheel was simplified. Starting from the polishing of a single abrasive particle, the relationship between the compression of the flag wheel and the polishing force during the polishing processes was explored. Based on the Hertz contact theory and the improved equal chord height error method, the step spacing was determined. Finally, the blade was clamped by the robot, and the comparison experiments of lateral polishing and longitudinal polishing were carried out by means of flag wheel polishing. Both polishing methods may ensure that the values of surface roughness are less than 0.4 μm and the profile errors are less than 0.08 mm, which may meet the dimensional accuracy and surface quality requirements of the blades.

Key words: leading and trailing edge, ellipse fitting, flag wheel, Hertz contact theory, equal chord height error method