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
Guoqing Xiong, Zhiwei Mao, Jinjie Zhang, Zijia Wang, Huailei Wang, Zhinong Jiang
Summary: Numerous studies have shown that both journal misalignment and bearing elastic deformation significantly affect lubrication performance. Recent research indicates that viscoelastic deformation is more useful than elastic deformation for determining the effects of strong impact loads. However, there have been no studies on the coupled effects of misalignment and viscoelastic deformation. Therefore, this study proposes a novel transient lubrication model that considers the influences of both misalignment and viscoelastic deformation, and investigates their coupled effects on lubrication performance.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
I. C. M. Filgueira Filho, A. C. Bottene, E. J. Silva, R. Nicoletti
Summary: Research shows that in textured journal bearings, the Chevron pattern and the oblong dimple pattern have significant effects on bearing performance, which can be either positive or negative.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Multidisciplinary
Jiaojiao Ma, Chao Fu, Hao Zhang, Fulei Chu, Zhanqun Shi, Fengshou Gu, Andrew D. Ball
Summary: This study investigates the coupling effects of non-Gaussian properties and misalignments on the performance of journal bearings, finding that non-Gaussian rough surfaces have a more significant influence on static performance, with negative skewness and large kurtosis increasing load capacity and decreasing friction coefficient. Non-Gaussian properties have a greater impact on performance than misalignment in hydrodynamic lubrication regime.
Article
Multidisciplinary Sciences
Evgeny V. Kharanzhevskiy, Aleksey G. Ipatov, Aleksey V. Makarov, Faat Z. Gil'mutdinov
Summary: This study introduces an innovative method to significantly reduce friction and wear in plain bearings operating without lubrication. By modifying the surface layers of steel-bronze pairs using short-pulse laser treatment and a specific carrier, superior friction performance is achieved. The modified friction pairs were tested under high-intensity sliding conditions and remained functional without the use of lubrication.
SCIENTIFIC REPORTS
(2023)
Article
Engineering, Multidisciplinary
M. B. Badawi, Taher H. Awad, I. M. El Fahham
Summary: This study applies artificial intelligence techniques to predict the performance of a plain journal bearing, showing their superiority over classical methods in terms of accuracy and speed. The data required for AI prediction is obtained using the finite difference method, and artificial neural networks and fuzzy logic techniques are utilized for performance parameter prediction.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Engineering, Aerospace
Changbao Yang, Zhisheng Wang, Zhe Chen, Yuanwei Lyu, Jingyang Zhang
Summary: In this study, the fluid-structure interaction between the gas film and elastic foils in gas foil journal bearings was investigated. The results showed that the stable fluctuations of flow field parameters varied at different positions, and the oscillating duration in the solid domain was shorter than in the fluid domain. The presence of elastic foils flattened the distribution of gas film pressure and improved the stability of the shearing flow. The research laid the foundation for studying unsteady fluid-structure interaction.
Article
Engineering, Electrical & Electronic
Steven Chatterton, Edoardo Gheller, Andrea Vania, Paolo Pennacchi, Phuoc Vinh Dang
Summary: This paper investigates the static characteristics of tilting-pad journal bearings lined with different materials. A full 3D thermal model is used to evaluate the temperature distribution in the bearing, while a finite element model is used to evaluate the deformation of the pads. The permissible operating range in terms of load and speed for each material is defined by considering the limits on the maximum temperature, permissible mechanical stress, and minimum oil-film thickness.
Article
Engineering, Mechanical
Jiaojiao Ma, Chao Fu, Weidong Zhu, Kuan Lu, Yongfeng Yang
Summary: This study analyzes the stochastic lubrications of a cylindrical hydrodynamic journal bearing with misalignment under uncertainties using the polynomial chaos expansion (PCE) and finite difference method. Various critical lubrication performance parameters are comprehensively studied by ensemble mean, standard deviation, probability density function, and cumulative distribution function. The findings provide insights into the significant effects of misalignment and different stochastic parameters on lubrication performance, guiding the robust design and analysis of general hydrodynamic journal bearings.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Mechanics
Airton Nabarrete, Gustavo de Freitas Fonseca
Summary: The paper investigates the application of mechanical couplings in rotating machinery, studying the effects of rotor misalignment on vibration stability through theoretical and experimental analysis. The finite element model and nonlinear response evaluation are utilized to assess the performance of the rotor system under rigid coupling misalignment.
Article
Engineering, Mechanical
Gaston Haidak, Xiaofeng Wei, Feiyue Li, Andrews Larbi, Dongyun Wang
Summary: This work presents a systematic analysis of the tribological properties and thermal exchange effect on the solid-fluid structure in an axial piston pump. It establishes a thermo-elastohydrodynamic model to study the pump and calculates the fluid film properties, friction forces, and leakage under normal operating conditions. The study analyzes the friction and leakage losses for different conditions and discusses the thermal effects on oil film properties and lubrication mechanisms. It provides methods to evaluate lubrication failure causes and emphasizes the criticality of heat exchange on energy and efficiency losses, as well as offers design suggestions for better axial piston pump performance.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Kai Wang, Lihua Yang, Haoze Wang, Xilong Ji, Kaidi Zhu
Summary: This paper investigates the dynamic response of offset-elliptical journal bearings (OEJBs) under the conditions of journal misalignment and sudden load. A hydrodynamic model is developed and validated for the transient analysis of the OEJBs. The study reveals that the misalignment and dynamic load have a significant impact on the transient performance of OEJBs.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2023)
Article
Engineering, Multidisciplinary
Peng Chen, Jianguo Ding, Hui Zhuang, Yu Chang, Xingbao Liu
Summary: This study investigates the combined influence of manufacturing errors, misalignment, and inertia effects on bearing performances. The extended Reynolds equation, which takes into account the inertia force of the compressible air film, is derived and solved using the streamline upwind Petrov-Galerkin finite element method (SUPG FEM). The theoretical models of manufacturing errors and misalignment are established and validated. The results show that manufacturing errors have a significant impact on bearing performances. Misalignment greatly affects the moment, while its effects on load capacity, radial stiffness, and angular stiffness are relatively small. Inertia effects can reduce bearing performances, except for journals with taper errors. When the film thickness is less than 20 μm, the influence of inertia effects on bearing performances can be ignored.
Article
Engineering, Mechanical
Xuewei Zhao, Shuhong Xiao
Summary: This study presents a three-dimensional model of gas foil bearings considering axial variation of structural deflection and investigates the effect of misalignment on bearing performance. The results indicate that second generation foil bearings exhibit better performance in the presence of misalignment.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Shuhui Cui, Le Gu, Michel Fillon, Chuanwei Zhang
Summary: A thermohydrodynamic model was used to study the influence of partial composite coatings on the thermal behavior of plain journal bearings. Results show that polytetrafluoroethylene, graphite, and diamond-like carbon coatings have different effects on thermal behavior, with full polytetrafluoroethylene coatings increasing maximum temperature and wall slip helping to decrease maximum temperature.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
