In-plane friction behaviour of a ferrofluid bearing

Journal article (2018)

Authors

S.G.E. Lampaert Mechatronic Systems Design - Mechanical, Maritime and Materials Engineering
Stefan Lampaert Mechatronic Systems Design - Mechanical, Maritime and Materials Engineering
J.W. Spronck Mechatronic Systems Design - Mechanical, Maritime and Materials Engineering
R.A.J. van Ostayen Mechatronic Systems Design - Mechanical, Maritime and Materials Engineering
Research Group
Mechatronic Systems Design (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2018 S.G.E. Lampaert, B. J. Fellinger, J.W. Spronck, R.A.J. van Ostayen
DOI: https://doi.org/10.1016/j.precisioneng.2018.05.013
More Info
expand_more

Published Date

2018

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Precision and Microsystems Engineering

Research Group

Mechatronic Systems Design

Abstract

Ferrofluid bearings have been demonstrated to be very interesting for precision positioning systems. The friction of these bearings is free of stick-slip which results in an increase of precision. More knowledge on the friction behaviour of these bearings is important for there application in precision positioning systems. This paper demonstrates that the friction of a ferrofluid bearing can be modelled by a viscous damper model and provides a basic model to predict the friction behaviour of a bearing design. The model consists of a summation of a Couette flow with a Poiseuille flow such that there is no net fluid transport under the bearing pads. The model is experimentally validated on a six degrees of freedom stage using ferrofluid bearings. A stiffness in the form of a closed-loop control gain is introduced in the system to create a resonance peak at the desired frequency. The damping coefficient can be identified from the peak height of the resonance, since the peak height is the ratio of total energy to dissipated energy in the system. The results show that the newly derived model can be used to make an estimate of the damping coefficient for small(∼1mm) stroke translations. Furthermore, the model shows that the load capacity of a ferrofluid pocket bearing is affected during sliding.