Title: Capacitive measuring method of the air-film thickness of aerostatic bearing

Authors: Yu Jing; Li Dongsheng

Addresses: College of Metrological Technology and Engineering, China Jiliang University, Hangzhou, 310018, China. ' College of Metrological Technology and Engineering, China Jiliang University, Hangzhou, 310018, China

Abstract: Aerostatic bearing is one of the essential and basic technologies of ultra-precision engineering, and air film vibration is one of the main factors affecting machining accuracy. This paper proposed a capacitive measuring method of the air-film thickness of aerostatic bearing, which took the restrictor and the working face as the two plates of the capacitive sensor, and the capacitive changed along with the changes of the air film thickness. After measuring the capacitance of the restrictor and the working face, the air film thickness was then calculated. The mathematical model between the capacitance and the air film thickness with concave restrictor was established. The experiments of aerostatic bearing film thickness measurement showed that compare to the inductor sensor, the capacitance measurement get an average error of 0.28 µm. The research of this paper provides a new method for air film thickness measuring of aerostatic bearings.

Keywords: aerostatic bearings; air film thickness; flat restrictor; concave restrictor; capacitive measuring; air film vibration; machining accuracy; mathematical modelling.

DOI: 10.1504/IJNM.2012.047013

International Journal of Nanomanufacturing, 2012 Vol.8 No.3, pp.173 - 183

Received: 20 Nov 2010
Accepted: 18 Jan 2011
Published online: 21 Aug 2014 *

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