Fabrication of micro-texture on cylindrical inner surface and its effect on the stability of hybrid bearing

In this paper, a removable through-mask electrochemical micromachining (EMM) is proposed for fabricating the microstructures with different sizes and structures on the inner surface of the hybrid bearing. By optimizing the machining parameters of EMM, micro-textures with considerable area consistency and excellent surface quality are obtained on the inner surface of the hybrid bearing. Subsequently, the stability tests of the non-textured bearing and other three textured bearings with various area ratios are carried out on the setup of hybrid rotor-bearing system to study the influence of micro-texture on the vibration characteristics and stability of the bearing rotor. The time domain, frequency domain, and axis trajectory of the rotor are compared and analyzed. The experiment results show that at low speed (2400 rpm), the micro-texture has little effect on the amplitude of bearing-rotor system. As the rotational speed increases, the amplitude of the rotor-bearing system gradually increases. It should be noted that the amplitude of specific micro-texture bearings is smaller than the non-textured bearing, but not all types of micro-texture perform like that. At 9000 rpm, the relative amplitude of one sample decreases by 22.6% compared with the non-textured bearing rotor system. Therefore, the micro-texture with reasonable size and structure could significantly reduce the vibration of the rotor-bearing system under the water film condition, which is of considerable significance to improve the stability of liquid film and provides a potential application background for high-speed bearing lubrication.