الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 73 |  |  |
| | | from | 73 | | |
Abstract
This work investigates the effect of adding reduced graphene oxide (rGO) to lithium-based grease on the performance of a deep groove ball bearing under different radial loads. An experimental test rig has been specially designed and constructed to conduct the required tests at a constant rotational speed of 1400 RPM and different test loads of 100, 1250, 2050, and 2250N. The test bearings were lubricated using grease-rGO mixtures with rGO additions of 0.5, 1, 2, 3.5, and 5wt.%. To assess the efficiency of each lubricant mixture, two measures have been used in this work: the consumed power and vibration levels in terms of root mean square (RMS). Other identical bearings were tested using graphite and multi-wall carbon nanotubes (MWCNTs) additives. It was found that grease-2wt.% rGO mixture provides the best lubrication condition as it reduces the power down to about one-fourth as compared to grease only. Both MWCNTs and graphite additives showed lower improvements in power saving as compared to rGO. Vibration measurements confirmed the previous findings by showing that all carbonaceous additives reduce the vibration levels (RMS value) by different percentages ranging from 11% to 17%. The highest percentage of reduction in RMS value has been manifested by 1wt.% rGO due to its outstanding damping effect.