The modern industry has a constantly increasing demand toward vibration-free rotating machines. Large rotor systems are commonly operated in the subcritical speed range. In the subcritical speed range, the bearings can be a significant source of vibration excitation. The bearing inner ring excites the rotor system at a frequency, which is the rotating frequency multiplied by the waviness component number in the roundness profile of the bearing inner ring. Consequently, subcritical resonance peaks can be observed when the bearing excitation frequency coincides with the rotor natural frequency.

The present study utilized a novel compensative 3D grinding to manufacture the bearing installation shaft into a geometry, which minimized the roundness error of the installed bearing inner ring. The decreased roundness error reduced the bearing based excitations to the rotor system. The successful grinding operation was confirmed with roundness measurements. The relevance of the method and the study was proven with rotor dynamic measurements.

The results clearly suggest that the compensative 3D grinding reduced the roundness error in both bearing inner rings of the rotor system. The decreased roundness error led to a significantly improved rotor dynamic response, which was observed as reduced amplitudes of the subcritical resonance peaks in the typical operating rotating frequency range.

The present study includes also a comparison between the proposed method and a previous steel strip method. The comparison shows that the proposed compensative 3D grinding method produced increasingly better roundness profiles and thus also better rotor dynamic responses.

现代工业对无振动旋转机的需求不断增长。大型转子系统通常在亚临界转速范围内运行。在亚临界转速范围内，轴承可能是激发振动的重要来源。轴承内圈以一个频率激励转子系统，该频率是旋转频率乘以轴承内圈圆度曲线中的波纹度数。因此，当轴承励磁频率与转子固有频率一致时，可以观察到亚临界共振峰。

本研究利用一种新颖的补偿3D磨削技术将轴承安装轴制成几何形状，从而最大程度地减少了已安装轴承内圈的圆度误差。降低的圆度误差减少了基于轴承的转子系统励磁。圆度测量证实磨削操作成功。转子动态测量证明了该方法与研究的相关性。

结果清楚地表明，补偿性3D磨削降低了转子系统两个轴承内圈的圆度误差。圆度误差的减小导致转子动态响应的显着改善，这是在典型工作旋转频率范围内，亚临界共振峰的幅度减小了。

本研究还包括了所提出的方法与先前的钢带方法之间的比较。比较结果表明，提出的补偿性3D磨削方法产生的圆度轮廓越来越好，因此转子的动态响应也越来越好。