Article
Engineering, Mechanical
Shaoyu Zhu, Xiangjun Zhang, Jun Sun, Dagang Wang
Summary: In this study, the static behavior of misaligned journal bearings under heavy loads was investigated using a non-Newtonian lubricant (pseudoplastic fluid with power-law relationship). The generalized average Reynolds equation for rough journal bearing under pseudoplastic lubricant flow was derived, using the average flow method of Patir and Cheng for model equation establishment. The numerical solution of bearing performance parameters was obtained using the finite difference method and the successive over-relaxation method, and it was found that surface roughness could partially compensate for the effects of liner elastic deformation and lubricant shear thinning. The derived generalized average Reynolds equation can be applied not only in the research of hydrodynamic lubrication but also in the research of mixed lubrication.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Shaoyu Zhu, Xiangjun Zhang
Summary: The modified average Reynolds equation for friction pairs with arbitrary three-dimensional rough surfaces lubricated by couple stress fluid is derived. The performance parameters under various factors, such as couple stress, surface roughness, journal misalignment, and thermal effect, are obtained using the finite difference numerical method. The results show that the surface roughness factor plays an important role in the performance of the friction pairs, even with small nominal eccentricity ratios.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Marine
Weixin Zhou, Yao Zhao, Hua Yuan, Jingxi Liu, Xiaoqiang Wang
Summary: This paper uses the influence coefficient factors method to analyze the contact pressure of misaligned bearings. The results show that the influence coefficient factors are greatly affected by the shape and constraints of the contact object. The proposed method is suitable for cylindrical shell contact analysis and has the same accuracy as FEM with half of the time consumption.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Mechanics
Peng Li, Hao Zhang, Xin Li, Zhanqun Shi, Sen Xiao, Fengshou Gu
Summary: The paper investigates the effect of manufacturing errors and misalignment on the lubrication behavior of journal bearings with micro-groove under dynamic loads. A mixed lubrication model is developed, considering factors such as mass conservation cavitation algorithm, asperity contact model, and force balance equation. The performance parameters of bearings with different surface profiles and micro-groove distributions are analyzed, and the results show that manufacturing errors and misalignment have a significant impact on the transient behavior of journal bearings.
Article
Engineering, Mechanical
Satish C. Sharma, Abhishek Kumar
Summary: A numerical simulation model for conical journal bearing system has been investigated in this study, showing that isotropic and longitudinal roughness on journal bearing surfaces can improve bearing performance but at the cost of frictional power loss. These results may inspire designers to develop better tribo-components.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Jiayu Gong, Kun Liu, Yong Zheng, Fanming Meng
Summary: This study investigates the misalignment issue of journal bearings supporting planet gears and develops a thermal-elastohydrodynamic (TEHD) model to analyze and verify its behavior. The results show that reducing modification amount, helix angle, and radial clearance can enhance the TEHD performance of the bearing.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Arun Bangotra, Sanjay Sharma, Reza Taufique, Deepak Byotra
Summary: The present study investigates the influence of surface waviness on the performance of a journal bearing operating in misaligned conditions. The finite element method is utilized to compute the lubricant pressure within the bearing and obtain the static parameters. Comparison is made between different waviness variables and a misaligned journal bearing without surface waviness. It is found that misalignment in both axes has a more severe effect on static performance parameters compared to misalignment in only one axis.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2023)
Article
Engineering, Mechanical
Woo-Ju Jeon, Sung-Ho Hong
Summary: A flexible structure is used to enhance the lubrication performance of a misaligned journal bearing. The bearing, which represents a sliding bearing, suffers damage from metal-to-metal contact caused by misalignment. To improve this issue, a journal bearing with a flexible structure is proposed. Numerical evaluation and elastohydrodynamic lubrication analysis considering elastic deformation are conducted, comparing lubrication performance based on variations in the flexible structure's geometry and minimum film thickness. Comparisons are also made between the journal bearing with and without the flexible structure. The flexible structure, in the form of a groove, is applied to the high load-bearing area of the journal bearing, experiencing elastic deformation through the generated oil film pressure to obscure a larger oil film. The numerical analysis demonstrates that the journal bearing with a flexible structure can enhance lubrication performance in misalignment conditions.
Article
Engineering, Chemical
A. Tiwari, B. N. J. Persson
Summary: This study examines the contact pressure of a cylinder in contact with an elastic half space with random surface roughness, finding that the pressure behavior varies with the dimensionless parameter alpha. The contact pressure is Hertzian-like for low alpha values and Gaussian-like for high alpha values, providing insight into the interaction between the cylinder and the rough surface.
Article
Nanoscience & Nanotechnology
Xintao Song, Wei Wu, Shihua Yuan
Summary: By integrating the average flow equation and Ng-Pan turbulence model using the boundary condition of mass conserving, a mixed lubrication model for misaligned bearing considering the effects of turbulence and cavitation was established. The results indicate that turbulence plays a significant role in high speed conditions, affecting the oil film pressure, moment, thickness, cavitation zone, and friction coefficient. Misalignment leads to an increase in friction in the mixed lubrication area and a slight decrease in the hydrodynamic lubrication area.
Article
Engineering, Mechanical
Adesh Kumar Tomar, Satish C. Sharma
Summary: This study comprehensively investigates the combined influence of surface roughness effects and piezo-viscous shear thinning lubricant on bearing performance. The results show that the longitudinal roughness surface pattern improves the stability of the journal bearing.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Mathematics, Applied
Rajesh C. Shah
Summary: This study investigates the effect of elastic deformation on load-carrying capacity in inclined slider-bearing and presents the numerical simulation results. The analysis shows that elastic deformation has no impact on load-carrying capacity.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Engineering, Mechanical
Liangyan Zheng, Hanhua Zhu, Shidong Fan, Jie Wu, Jiyin Cao
Summary: This study investigates the combined effects of couple stress and surface roughness on the lubrication performance and regime transition of misaligned hydrodynamic journals. New lubrication models considering misalignment angle, couple stress, and surface roughness were developed. Results show that the relationship between the minimum film thickness, maximum film pressure, and friction coefficient with respect to couple stress parameters is opposite to that with respect to misalignment angle. The speed of regime transition and the minimum friction coefficient increase with misalignment angle but decrease with couple stress parameter.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Mechanical
Juan Guo, Guo Xiang, Jiaxu Wang, Yankui Song, Jianlin Gai, Haiming Dai
Summary: This paper introduces a method of one-side profile modification for reducing the edge wear caused by journal defection in misaligned journal bearings. The effectiveness of the modification is confirmed through numerical calculations. The results indicate that the reasonable design of one-sided profile modification can increase the minimum film thickness at the edge of the bearing and reduce rough contact, thus improving the anti-wear performance of the misaligned journal bearing.
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2022)
Article
Mechanics
Fangrui Lv, Xinjie Zhang, Cuicui Ji, Zhushi Rao
Summary: Due to their low load-carrying capacity, low-viscosity lubricated bearings can operate easily in a mixed-lubrication regime. This study proposes a simulation approach that considers the effects of local turbulence on the transient characteristics of mixed-lubrication bearings and validates the model through experiments.
