On-machine dressing of cup-shaped diamond grinding wheels for high-quality hemispherical resonator manufacturing

Abstract

Abstract

The fused silica hemispherical resonator, a critical component in hemispherical resonator gyroscopes, requires exceptional surface integrity to ensure high quality factors (Q factors) and minimal frequency splitting. Ultra-precision grinding is commonly used for shaping such brittle materials, and the performance of the grinding wheel plays a crucial role in machining outcomes. This study integrates one-step forming with a bronze-bonded cup-shaped diamond grinding wheel and on-machine dressing techniques targeting both the cutting edge and wheel matrix. A systematic investigation from tool geometry to resonator performance is conducted. The radial runouts of the cutting edge and matrix are significantly reduced to 5.666 and 2 μm, respectively. This improvement leads to fewer surface defects and shallower grinding marks, yielding a surface roughness below 0.02 μm and reducing the peak-to-valley error by 73% to 85.27 nm. Geometric accuracies at the resonator level are improved, with circularities of the inner and outer hemispheres and concentricity reduced by 46.15%, 57.89%, and 28.57%, respectively. The Q factor of the resonator is improved to 3.17 × 107, while frequency splitting is reduced to 0.0156 Hz. These results confirm that simultaneous dressing enhances tool integrity, enabling high-quality surface generation and improved resonator performance. This study provides a viable approach for fabricating high-Q resonators.