Development of hydrodynamic micro-bearings

16th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications

物理学;能源学

Wang, P.^1 ; Zhang, J.^1 ; Spikes, H.A.^1 ; Reddyhoff, T.^1 ; Holmes, A.S.^2

Tribology Group, Department of Mechanical Engineering, Imperial College London, London

SW7 2AZ, United Kingdom^1

Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, London

SW7 2AZ, United Kingdom^2

关键词: Energy Harvester;    Friction modifier additives;    Friction performance;    Hydrodynamic bearings;    Hydrodynamic theory;    Low friction;    Low-viscosity liquids;    Micro-bearings;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/773/1/012020/pdf
DOI  :  10.1088/1742-6596/773/1/012020

来源: IOP

【 摘 要 】

This paper describes the modelling and testing of mm-scale hydrodynamic bearings which are being developed to improve the efficiency of a cm-scale turbine energy harvester, whose efficiency was previously limited by poorly lubricated commercial jewel-bearings. The bearings were fabricated using DRIE and their performance was assessed using a custom built MEMS tribometer. Results demonstrate that acceptably low friction is achieved when low viscosity liquid lubricants are used in combination with an appropriate choice of friction modifier additive. Further reduction in friction is demonstrated when the step height of bearing is adjusted in accordance with hydrodynamic theory. In parallel with the experiments, hydrodynamic lubricant modelling has been carried out to predict and further optimize film thickness and friction performance. Modelling results are presented and validated against experimental friction data.