Experimental investigation of shock responses of cantilever-shaft design hydrodynamic bearing spindle motors

Open-loop radial operating shock responses of spindle motors are studied experimentally. Unlike a ball bearing spindle, a hydrodynamic bearing (HDB) is able to suppress the vibration within a few milliseconds. However, HDB spindles have higher response amplitudes than ball bearing spindles. HDB response amplitude is linearly proportional to the shock impulse amplitude at the current test range. A longer shock duration has a higher response amplitude. Reducing compliance of the thrust bearing does not affect the shock response amplitudes but does reduce the power consumption.