Vibration Characteristics On Ball Bearing Operated With Hexagonal Boron Nitride Nanoparticles Mixed With Conventional Diesel Engine Oil

Several developments on lubricants have been proven to reduce the friction and wear on mechanical parts. The addition of solid lubricants such as graphite, boric acid, graphene and nano-diamond showed an improved anti-wear, load- carrying and friction reduction. Therefore, as an environmentally friendly inorganic solid lubricant, hexagonal boron nitride (hBN) is chosen as an attractive performance-enhancing additive. hBN is widely used as lubricant additive, electrical insulators, materials part, aeronautics and space application. In addition, hBN nanoparticles also acts as promising additives to reduce wear and friction in tribology field. However, there is lack understanding about the performances of hBN nanoparticles in reducing the vibration characteristic on ball bearing. The aim of this research is to determine the vibration characteristics on ball bearing operated with hexagonal boron nitride (hBN) nanoparticles mixed with diesel engine oil types SAE 15W40 in the vibration monitoring condition field. This work is intended to determine the performance of hBN nano-lubricant as an additive in the reduction of rolling element bearing vibration amplitude. In this study,experimental works were conducted on the new and defected bearings submerged with different concentration of hBN nanolubricants namely 0.0 vol.%, 0.1 vol.%, 0.2 vol.%, 0.3 vol.%, 0.4 vol.% and 0.5 vol.% of hBN nano-lubricants. The vibration characteristics were acquired using fabricated test rig, which consist of new and defected bearing, induction motor, unbalanced rotor, an accelerometer and data acquisition device. The vibration signal generated by the bearings were detected by an accelerometer placed at the top of the bearing housing measuring in vertical direction. The time waveform and amplitude spectrum were used in measuring the effect of hBN nano-lubricant on the vibration performance of the rolling element bearing.In the time waveform, the overall effect of hBN was investigated by determining the crest factor (CF) while the effect of hBN on specific faults such as outer race and inner race defects was investigated using the amplitude spectrum. The findings from the bearing vibration were supported by the tribological characteristics investigation such as wear scar diameter and agglomeration. From experimental work, 0.2 vol.% of concentration found was the optimum volume for new bearing and 0.4 vol.% of concentration of hBN gives the optimum volume of concentration for defected bearing in reducing vibration amplitude compared to the other volume of concentration