Non-Linear Dynamic Analysis on Hybrid Air Bearing-Rotor System under Ultra-High Speed Condition.

Laiyun Song,Guoqin Yuan,Yalin Ding,Hongwen Zhang,Kai Cheng

doi:10.3390/ma15020675

Laiyun Song, Guoqin Yuan + Show 3 more

Open Access

https://doi.org/10.3390/ma15020675

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Abstract

The non-linear dynamic behavior of a hybrid air bearing-rotor system is very complicated and requires careful attention when designing to avoid spindle failure, especially under ultra-high speed condition. In this paper, the rotor trajectory of a hybrid air bearing-rotor system is obtained by solving the unsteady Reynolds equation and motion equations simultaneously. The typical non-linear behavior of hybrid air bearing-rotor systems is illustrated with the analysis of the rotor trajectory, the phase angle, time domain vibration and power spectral density. Furthermore, the influences of the rotor mass, external load, rotating speed and unbalanced mass on the non-linear behavior are investigated. Finally, the effect of structure parameters on the rotor trajectory is studied and the phenomenon under ultra-high speed condition is illustrated, which provides some new guidelines on the ultra-high speed air spindle design.

Highlights

The production of optical lenses with high surface quality is mainly carried out on machines equipped with high-precision air spindles [1], due to their inherent advantages in high motion precision [2,3]
The high-precision air spindles operated at ultra-high speed condition can be characterized as the ultra-high speed hybrid air spindle, in which the aerostatic effect and the aerodynamic effect are equivalent in the load capacity of the spindle [4]
The non-linear dynamic behavior of the system is shown in Figure 3 when the rotating speed is 30,000 r/min, the system external load is 10 N, the rotor mass is 10 g and the unbalanced mass is 0.01 g

Summary

Introduction

The production of optical lenses with high surface quality is mainly carried out on machines equipped with high-precision air spindles [1], due to their inherent advantages in high motion precision [2,3]. Wang et al designed and calculated a series of non-linear dynamic parameters such as phase angle trajectory, power spectrum and bifurcation diagram [7] to study the non-linear behavior of the aerostatic bearings [8], porous bearings [9], self-acting bearings [10], etc., Belforte et al designed a high-speed electrospindle for 100 krpm and analyzed the static and dynamic runout of the spindle by solving the time-domain Reynolds equation for gas film together with the equation of motion of the rotor [11]. The non-linear behavior of hybrid gas journal bearings under ultra-high speed condition is studied by solving the unsteady Reynolds equation and rotor motion equations simultaneously. The effect of the structure parameters on the rotor trajectory of a hybrid air bearing-rotor system under ultra-high rotating speed condition are studied and the effect of the ultra-high speed condition is emphasized, providing new guidelines for designing the ultra-high speed air spindle

Mathematical Model

Results and Discussion

Conclusions