Ultra-precision grinding machine design and application in grinding the thin-walled complex component with small ball-end diamond wheel

Complex structural components with small concave surfaces are widely needed in aerospace, optics, and electronic industry. On account of the interference between grinding wheel and workpiece and small concave surfaces, traditional grinding machine cannot realize the grinding process; hence, a specialized grinding machine tool with on-machine electric discharge truing function is needed. After analyzing the structural characteristics and processing requirements of the component, the kinematic chain and configuration were designed. The structure of the machine tool was divided into four function modules, and each module was designed, analyzed, and optimized, respectively. Then the finite element analysis (FEA) of the whole machine tool was conducted including static, modal, and harmonic response analysis to verify the performance of the machine and identify the weak links of the structure loop. The error model was established by screw theory to study the quantitative relationship between the static deformations and processing accuracy. Both finite element analysis and error model can provide guidance for further optimization. Finally, the performance of the machine tool was evaluated by the grinding and on-machine truing experiments, achieving the profile accuracy (PV) of 0.339 μm, surface roughness (Ra) of 50.2 nm, and the grinding wheel surface with diamonds distributing homogeneously. The results indicate that the developed machine tool can well satisfy the processing requirements of the component.