Article
Engineering, Mechanical
Xincong Zhou, Fuming Kuang, Jian Huang, Xueshen Liu, Konstantinos Gryllias
Summary: Frictional vibration in water-lubricated rubber bearings can severely impact the reliability and performance of underwater vehicles. The hardness, thickness, and concavo-convexity of the rubber layer significantly affect the damping properties of the bearing system, with hardness being the most important factor, followed by thickness and surface radius.
TRIBOLOGY TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Yanfeng Han, Ting Tang, Guo Xiang, Hang Jia
Summary: This study investigates the impact of propeller shaft deflection on the fluid-solid-heat coupling performance of water lubricated rubber stern bearing, and develops a model to validate the findings. Results suggest that under heavy load conditions, the deflection of the stern shaft should be taken into account in the analysis of FSH performance of the JWR system.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Mechanical
Shengdong Zhang, Zhilin Long, Xiuying Yang
Summary: This research proposes a magnetorheological fluid-lubricated rubber stern bearing test ring to study the effects of temperature, magnetic field strength, and eccentricity ratio on lubrication performance. By solving the Reynolds equation with the finite difference method and successive over-relaxation method, it is found that bearing capacity can be improved and friction coefficient reduced by adjusting these parameters. The results of this study may offer valuable theoretical and experimental support for the design of rubber stern bearings lubricated with this type of magnetorheological fluid.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2021)
Article
Engineering, Mechanical
M. Wodtke, W. Litwin
Summary: The research focuses on thermal phenomena related to the operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests showed that the intensity of forced axial flow significantly affects the bush temperature. Numerical simulations revealed that restricted axial flow leads to backflow of water through the grooves, resulting in a higher backflow temperature than the supply temperature and an increase in bearing bush temperature.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Jinsheng Qiao, Guangwu Zhou, Wei Pu, Renpan Li, Min He
Summary: This study establishes a turbulent mixed lubrication model of water lubricated rubber bearings (WLRBs), revealing the effect mechanism of turbulence in these bearings. The rationality of the model is verified through experiments, and optimal axial misalignment and radius clearance that can maximize the turbulent force are determined.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Marine
Chang-Gang Lin, Ming-Song Zou, Hai-Cheng Zhang, Li-Bo Qi, Shu-Xiao Liu
Summary: The study established a mechanism for friction-induced vibration and noise in water-lubricated stern bearings, finding that changes in various parameters can significantly affect the stability and nonlinear response of the system, providing important guidance for low noise design.
INTERNATIONAL JOURNAL OF NAVAL ARCHITECTURE AND OCEAN ENGINEERING
(2021)
Article
Engineering, Marine
Wu Ouyang, Qilin Liu, Jinhua Xiao, Jian Huang, Zhuo Zhang, Lei Wang
Summary: A full-size test rig of water-lubricated stern bearing (WSB) with an elevation adjustment device was constructed and various measurement devices were used to study the lubrication characteristics of the bearing under different conditions. The distribution lubrication characteristic of WSB at the axial direction was observed, and the bearing lubrication region was divided into three sub-regions with different take-off speeds. The negative pressure and hull deformation were found to affect the lubrication characteristics and loads carried by the water film and asperity contact.
Article
Engineering, Mechanical
Gang Liu, Ming Li
Summary: Experimental results show that the water film can bear a certain negative pressure without cavitation, and the bearing load increases faster as the rotating speed increases, indicating turbulent flow at high rotating speeds.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Guangwu Zhou, Jinsheng Qiao, Wei Pu, Ping Zhong
Summary: The present study improves the conventional water-lubricated rubber bearing (WLRB) by using a tilting-pad structure and develops a mixed elastohydrodynamic (Mixed-EHD) model for water-lubricated rubber tilting-pad journal bearing (WLRTPJB). The study investigates the influence of structural and operating parameters on the tribological properties and pad swing characteristics. The results show that the WLRTPJB has a lower contact load, especially under heavy load conditions, and provide optimal pivot offset and preload factor to minimize contact pressure. Moreover, the equilibrium tilting-pad angle is sensitive to changes in design and operating parameters. This study has certain guiding significance for the design optimization of WLRB.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Pengfei Wang, Hebin Jiang, Mao Liu, Liang Zhang, Songlin Xu
Summary: Lubricant exhibits abnormal strengthening and toughening effects during high-speed perforation, improving the resistance of laminar aluminum through reducing stress concentration, delaying failure displacement, and increasing dissipated energy. This phenomenon is significant for understanding the friction and fracture evolution in developing membrane-like protective structures.
MATERIALS & DESIGN
(2022)
Article
Engineering, Mechanical
Bin Xiao, Xiaolin Zheng, Yi Zhou, Dan Yao, Yang Wan
Summary: The study found that under seawater conditions, the surface friction coefficient and wear rate of water-lubricated rubber bearings alternate, and seawater not only acts as a lubricating medium, but also brings microstructure, enhancing the lubricating effect.
INDUSTRIAL LUBRICATION AND TRIBOLOGY
(2021)
Article
Thermodynamics
Hao Zhang, Chengqing Yuan, Zusheng Tan
Summary: This paper investigates the effect of operating conditions on water lubricated stern bearing temperature characteristics, discussing the evolution mechanism of the temperature field and finding the correlation between bearing friction coefficient and maximum temperature. The study determines the conditions for better cooling performance, providing a theoretical basis for the operation monitoring of WLSBs and the development of new materials.
ADVANCES IN MECHANICAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Qilin Liu, Wu Ouyang, Qichao Cheng, Jinjun Li, Qizhi Cheng, Ruiqing Li
Summary: This paper investigates the lubrication and dynamic characteristics of water-lubricated stern bearing under service conditions. It proposes a test scheme to analyze the pressure distribution and spatial shaft position of the bearing. The experiment reveals the pressure bias and bidirectional shaft inclination phenomenon, and a dynamic model considering bidirectional shaft inclination and lining deformation is established. The study explores the influences of various factors on lubrication and dynamic characteristics and provides guidance for the design and optimization of such bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Mechanical
Qilin Liu, Wu Ouyang, Ruiqing Li, Yong Jin, Tao He
Summary: This paper aims to study the demand of underwater vehicles for water-lubricated stern bearings with low noise, low vibration, high load capacity, and long service life. A series of experiments was conducted to analyze the lubrication and vibration characteristics of three test bearings with different bushing materials and structures. The results indicate that under extreme working conditions, the modified polyurethane bearing shows the best comprehensive performance. Specific pressure and environment temperature significantly influence the bearing performance, while flow rate has limited effect. The research provides important references for the material and structure design and performance testing of water-lubricated stern bearings.
Article
Engineering, Mechanical
Taiwei Yang, Hanhua Zhu, Shidong Fan, Jie Wu, Junlang Yuan, Liangyan Zheng
Summary: This article investigates the influence of installation errors on the lubrication characteristics of sliding bearings in ship shafting. By establishing a hydrodynamic lubrication model and using numerical methods, it is found that installation errors can result in a decrease in the lubrication status of the bearings, with a decrease in the minimum film thickness and an increase in the maximum film pressure. Moreover, the aft stern bearing is more sensitive to vertical installation errors, while the fore stern bearing is more sensitive to lateral installation errors.
Article
Engineering, Mechanical
Yankui Song, Ke Xiao, Guo Xiang
Summary: The novelty of this study lies in constructing an Entropy-based wear and fluid-solid-thermal (FST) coupled model for journal bearings, and revealing the transient interaction behavior between wear evolution and FST evolution during repeated starting and stopping. The wear rate is measured experimentally, and the contact temperature, friction coefficient and normal contact force are obtained from the validated FST model. Wear tests and numerical calculations are conducted to validate the predicted wear rate and investigate the time-varying wear and FST evolution of journal bearings.
Article
Engineering, Mechanical
Xin-long Liu, Xin Guan, Yuan Zhong, Qian Xiao, Yong Cao, Wu-lue Zhang, Song Zhang, Yi-ting Zheng, Ming-sheng Gao, Dao-yun Chen, Wen-bin Yang
Summary: Gaps in the conductor rail joints of intercity trains have an impact on current transmission and the wear of carbon skateboards. These gaps decrease the coefficient of friction, increase electrical contact resistance, and affect the wear rate of carbon skateboards.
Article
Engineering, Mechanical
Yuhang Wu, Conglin Dong, Xiuqin Bai, Chengqing Yuan
Summary: The study developed a new composite material by incorporating hexagonal boron nitride (h-BN) particles into a thermoplastic polyurethane (TPU) matrix, which exhibited excellent self-lubricating properties and reduced frictional excitation forces. The addition of h-BN particles effectively reduced the coefficient of friction, decreased fluctuation amplitude, enhanced wear resistance, and attenuated vibration behaviors.
Article
Engineering, Mechanical
Tiancheng Ouyang, Xiuyang Sun, Wentao Tang, Yinxuan Li, Zhi Qun Tian, Yanzhou Li
Summary: By adding nitrogen-doped graphene and C60 nanoparticles to the lubricant, a highly efficient nano-lubricant with vibration and noise reduction properties is synthesized.
Article
Engineering, Mechanical
Xin Zhuo, Jun Cao, Haibo Huang, Li Liu, Xinkun Suo, Peiqing Ye, Zeshan Abbas
Summary: A polymer coating prepared by liquid spraying technology on the surface of 20CrMo steel demonstrates good tribological and anti-cavitation erosive properties. It can effectively replace CuPb24Sn copper alloy in valve plates for pumps under different lubrication conditions. The coating exhibits adhesive wear and reduces frictional loss, and mainly shows abrasive wear under complex working conditions. Its lipophilicity, high hardness to elastic modulus ratio, and corrosion resistance are the main influencing factors for its performance.
Article
Engineering, Mechanical
Md. Aminul Islam, Jiaren (Jimmy) Jiang, Yongsong Xie
Summary: Erosion-corrosion is a major factor in material loss and reduced useful life of hydro-transport equipment. This study evaluates the erosion-corrosion characteristics of different materials and finds that matrix wear affects the degradation of carbides. Sufficient wear and corrosion resistance in the surrounding matrix are important for good erosion-corrosion resistance.
Article
Engineering, Mechanical
Andre Dubois, Oussama Filali, Laurent Dubar
Summary: This study investigates the effect of surface roughness, contact pressure, and lubrication on the onset of galling in aluminum 6082-T6 using a pin-on-plate tribometer. The experimental results show that the roughness and lubricants play a significant role in preventing galling.
Article
Engineering, Mechanical
Jizhan Wu, Peitang Wei, Guoqiang Liu, Difa Chen, Xiuhua Zhang, Taimin Chen, Huaiju Liu
Summary: This study conducted a comprehensive evaluation of the DLC coating treatment on the loading capacity of gears and characterized the surface features and fatigue performance. The results demonstrate that DLC coating significantly improves the hardness and surface residual compressive stress of the gears, as well as enhances their contact fatigue performance.
Article
Engineering, Mechanical
Yangping Liu, Hwaran Lee, Annsley Mace, Jeremy L. Gilbert
Summary: An AFM-based single asperity tribology method was used to investigate the wear performance of carbides and base metal matrix in high carbon CoCrMo alloy. The wear behavior of the two types of carbides was stress-dependent and influenced by chemical composition. Cr-rich carbides exhibited higher wear resistance compared to Mo-rich carbides.
Article
Engineering, Mechanical
Zdenek Riha, Michal Zelenak, Akash Nag, Jakub Poloprudsky, Tomas Kruml, Sergej Hloch
Summary: This study investigates the erosion performances of a high-speed modulated jet (MWJ) and continuous water jet (CWJ). By comparing different nozzles and water jet powers, the effects of modulated and continuous jets on aluminum alloy were studied. The results show that under certain conditions, modulated jet can create deeper and sharper grooves while reducing the impact of lateral flow.
Article
Engineering, Mechanical
Chunyu Yu, Weipu Li, Yang Guo, Xianbin Sun, Fanli Hong, Ning Sun, Qinghai Zhang
Summary: This study explores the relationship between the wear rate of train brake pads and its features, and proposes a method for predicting the wear rate suitable for small sample data. Grey relational analysis and Pearson correlation analysis are used to determine the preferred features that affect the wear rate, and a BOA-BP model is established for prediction. The results show that BOA-BP exhibits better advantages in prediction with small samples.
Article
Engineering, Mechanical
Shan Yin, Xin Zhao, Shuangchao Huang, Zefeng Wen, Xuesong Jin
Summary: This study simulated the rolling contact of a driving wheelset over tangent and curved tracks at a speed up to 500 km/h using an explicit finite element approach to derive creep curves. The comparison between quasi-steady curves and transient curves in the presence of rail corrugation helped to identify cases where traditional theories are inapplicable and where transient effects must be considered. Additionally, the study further analyzed the influence of middle/high-frequency vibrations in the presence of rail corrugation.
Article
Engineering, Mechanical
Jiyao Zhang, Yuanlie Yu, Junlei Tang, Yingying Wang, Honggang Sun, Kaikai Song, Jianhong Gong, Pingping Liu, Xiaoming Liu, Lina Hu, Parthiban Ramasamy, Juergen Eckert
Summary: The influence of high-carbon addition on the microstructure, hardness, and wear behavior of CoCrNi alloy was investigated. It was found that the addition of carbon resulted in the formation of carbide particles, enhancing the hardness and improving the wear resistance. Fracture and detachment of hard carbides during friction introduced additional abrasive particles, transitioning the wear mechanism from adhesive-dominated to abrasive-dominated.
Article
Engineering, Mechanical
Yanfei Liu, Shengtao Yu, Ruize Zhang, Xiangyu Ge, Wenzhong Wang
Summary: This study reports the tribological behavior of nanodiamond plate (NDPL) as a nanoadditive for the first time and compares it with nanodiamond particles (NDPA). The results show that NDPL provides better lubrication performance at higher concentrations, and the sliding between NDPLs and the structural transformation from sp3 to sp2 carbon play a crucial role in lubrication and wear resistance.