Experimental investigation on the influence of a multi-scratched shaft on hydrodynamic journal bearing performance

Bouyer, J.; Alexandre, Y.; Fillon, Michel

doi:10.1016/j.triboint.2020.106543

Cited by 15 publications

(3 citation statements)

References 11 publications

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“…The scratches on the shaft surfaces will also significantly affect the bearing system, so scholars have started studying the influence of shaft scratches on bearing lubrication performance [30]. Jean et al [31,32] found that different scratch locations could change the fluid pressure distribution. Branagan [33,34] simplified the longbearing model into a short-bearing model to study the effects of scratch locations on the performance of oil-lubricated bearings.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Scratches on the Tribological Performance of Friction Pairs Made of Different Materials under Water-Lubrication Conditions

Liang,

Guo

et al. 2023

Lubricants

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Water-lubricated bearings are widely used in marine equipment, and the lubricating water often contains hard particles. Once these particles enter the gap between the bearing and the shaft, they can scratch the smooth surfaces of the shaft and bearing, influencing the working performance of the bearing system. To investigate the effect of scratch parameters on tribological performance, this paper conducts multiple block-on-ring experiments and constructs a mixed-lubrication model under water-lubrication conditions. The results show that among the three commonly used bearing materials, the tribological performance of graphite block is the most sensitive to scratches on the test ring surface. Under the condition of one scratch (N = 1), the loading area of water film pressure is divided into two separate zones (a trapezoidal pressure zone and an extremely low-pressure zone). In addition, the variation of maximum water film pressure is determined by the positive effect (hydrodynamic pressure effect of fluid) and negative effect (“piercing effect” of the asperities). Compared with the scratch depth and scratch location, the scratch width has the most significant effect on the tribological performance of the block-on-ring system. The maximum contact pressure is located at both edges of the scratch due to the formation of a water sac structure. The scratch has a great influence on the transition of the lubrication state of the block-on-ring system. The existence of scratches increases the critical speed at which the lubrication state transits from mixed-lubrication to elastohydrodynamic lubrication, and the critical speed is directly proportional to the scratch width.

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Section: Introductionmentioning

confidence: 99%

The Influence of Scratches on the Tribological Performance of Friction Pairs Made of Different Materials under Water-Lubrication Conditions

Liang,

Guo

et al. 2023

Lubricants

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“…The results were analyzed and compared by Bouyer et al using a thermo-hydrodynamic (THD) numerical model (Bouyer et al , 2019). Vo et al developed a numerical THD program using the finite volume method to simulate the effects of scratches on the performance of journal bearings and compared the results with the scientific literature (Vo et al , 2021) and experimental measurements (Bouyer et al , 2021).…”

Section: Introductionmentioning

confidence: 99%

A numerical model with nonuniform grids for the analysis of dynamic characteristics of scratched tilting-pad bearings

Fan,

Yuan,

Chen

et al. 2023

ILT

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Purpose The purpose of this study is to present a numerical model for scratched tilting-pad bearings (STPBs) with nonuniform grids. In addition, the model is used to reveal the effects of the structural parameters of bearings on the dynamic characteristics of STPBs under impact loading. Design/methodology/approach By combining the Reynolds equation, the flow balance equation and the assumption of adiabatic bearings and shafts, a thermo-hydrodynamic model with nonuniform grids of scratched journal bearings was built. Describing the motion of the shaft using the Euler method and introducing the pad-tilting-angle modification equation, a dynamic model of STPBs was established. Findings The occurrence of scratches in tilting-pad bearings yields great sensitivity to impact loading. Less width-to-diameter ratio and larger clearance ratio reduce the minimum film thickness and enlarge the maximum film pressure, which may lead to bearing collision or abrasion. Moreover, STPBs with larger clearance ratios take longer to recover from impact loading. Originality/value This work is original and a valuable reference for the analysis of the dynamic characteristics of STPBs. The effects of other factors on the dynamic characteristics of STPBs can be further investigated based on this model.

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“…The tribological properties of water-lubricated polymer stern tube bearings is one of the key factors affecting the safety and reliability of a ship's propulsion system [9]. Actually, when large propulsion shafts are subjected to heavy loads, low speeds, turning, and starting or stopping states, hybrid lubrication, boundary lubrication, or dry friction occurs between the wear surfaces of polymer bearings and the propulsion shafts, which results in severe friction processes, eventually causing large frictional forces [10][11][12][13]. Thus, the materials at the contact surfaces of polymer bearings deform easily along the friction direction, leading to an unstable contact state, which causes violent fluctuations in the friction forces [14,15] and eventually generates frictional vibrations and noise [16].…”

Section: Introductionmentioning

confidence: 99%

Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles

Dong

2022

Materials

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The insufficient lubrication of the contact interface between moving parts can easily induce severe friction vibration and noise under extreme working conditions, which will threaten the service life and reliability of polymer moving components, including water-lubricated stern tube polymer bearings. Thermoplastic polyurethane (TPU) modified by polytetrafluoroethylene (PTFE) particles was developed. The effects of PTFE on the wear and vibration behaviors of modified TPU sliding against the ZCuSn10Zn2 ring-plates were investigated. The coefficients of friction (COFs), wear mass losses, wear morphologies, frictional vibration, and noise were analyzed synthetically. The results showed that a suitable mass content of PTFE reduced the COFs and wear mass losses of the TPU composites by more than 50% and 40%, respectively, while presenting an excellent friction reduction. The lower COFs of modified TPU showed a small fluctuation amplitude and eliminated vibration waveforms at high vibrational frequencies, which was useful for reducing frictional vibration and noise. The knowledge gained in this study is useful for a better understanding of the wear behaviors of polymer composites, as well as for the design a new polymer material with good self-lubricating and frictional vibration and noise reduction properties.

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Experimental investigation on the influence of a multi-scratched shaft on hydrodynamic journal bearing performance

Cited by 15 publications

References 11 publications

The Influence of Scratches on the Tribological Performance of Friction Pairs Made of Different Materials under Water-Lubrication Conditions

The Influence of Scratches on the Tribological Performance of Friction Pairs Made of Different Materials under Water-Lubrication Conditions

A numerical model with nonuniform grids for the analysis of dynamic characteristics of scratched tilting-pad bearings

Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles

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