这里所谈的误差是指球面铣磨中出现的深菊花纹、边厚差和偏心。深菊花纹是由于筒形铣磨砂轮的径向跳动和轴向跳动引起的,这两种跳动主要是砂轮制造误差造成的。铣磨机轴自身跳动一般都很小,影响不大。这两种跳动除造成深菊花纹外,还造成不规则的非球面。实测表明砂轮轮缘处的径向跳动有时达0.5mm以上,轴向跳动达0.2mm,对玻璃的破坏层深度可达0.2mm以上, The error here refers to deep chrysanthemums that appear in spherical milling, side thickness differences and eccentricities. Deep chrysanthemum pattern is caused by the radial runout and axial runout of the cylindrical milling wheel, which are mainly caused by the manufacturing error of the grinding wheel. Milling mill shaft itself is generally small, little effect. In addition to these two beats caused by deep chrysanthemum pattern, but also cause irregular aspheric surface. The measured results show that the radial runout at the wheel rim sometimes reaches more than 0.5mm and the axial runout reaches 0.2mm. The depth of damage layer to the glass can reach 0.2mm or more,