Article
Engineering, Marine
Wu Ouyang, Qilin Liu, Qichao Cheng, Gao Wan, Yong Jin
Summary: In this study, the centralized dynamic characteristics of traditional journal bearings were investigated. It was found that a distributed dynamic characteristic will be generated along the axial direction for journal bearings with a large aspect ratio. A suitable loading method was developed, and a corresponding test-rig was set up. Two excitation methods were proposed. Experimental results showed that the eight-time cross excitation method had a higher signal-to-noise ratio and provided more accurate identification results. The study also revealed that shaft bending is the main factor contributing to the increase in local dynamic characteristic coefficients.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Sanyam Sharma, Chimata M. Krishna
Summary: This study analyzed the stability of non-circular offset bearings using the finite element method, with selected input parameters such as eccentricity factor and aspect ratio. Output parameters including load, critical mass, whirl frequency ratio, and threshold speed were computed and plotted, showing that micropolar lubricated circular offset bearings exhibit high stability at higher eccentricity factors and aspect ratios.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Bo Xu, Hun Guo, Xiaofeng Wu, Yafeng He, Xiangzhi Wang, Jianhui Bai
Summary: This paper analyzes the influence of turbulent, inertia, and misaligned effects on the performance of high-speed water-lubricated hydrodynamic journal bearings, finding that these effects significantly enhance the characteristics and stability of the bearings.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Marine
Yandong Gu, Jinwu Cheng, Hao Sun, Ao Liang, Li Cheng
Summary: This study investigates the static characteristics of water-lubricated hydrodynamic journal bearings under three-dimensional slip velocity boundary conditions. The CFD method is verified under the non-slip boundary condition and a three-dimensional slip velocity equation based on the Navier slip velocity boundary condition is proposed. The results show that with an increase in slip length, the load capacity and friction power decrease, while an increase in attitude angle leads to an increase in load capacity and friction power.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Thales Freitas Peixoto, Diogo Stuani Alves, Felipe Wenzel da Silva Tuckmantel, Gregory Bregion Daniel, Tiago Henrique Machado, Katia Lucchesi Cavalca
Summary: This work presents a three-dimensional, variable viscosity model for multi-lobed journal bearings, which can estimate the pressure and temperature distributions of the lubricant and its effect on the hydrodynamic forces and coefficients. The study investigates the impact of thermal boundary conditions and preload on the bearing performance.
MECHANISM AND MACHINE THEORY
(2022)
Article
Engineering, Mechanical
Wu Ouyang, Qichao Cheng, Yong Jin, Qilin Liu, Bin Wang, Lei Wang
Summary: By calculating a three-dimensional mechanical model, a fluid-solid coupling model for water-lubricated journal bearings was proposed, showing the impact of journal bending on lubrication performance distribution and high pressure peaks at both ends of the bearing. As eccentricity increases and Young's modulus of lining decreases, the aggregation phenomenon intensifies.
TRIBOLOGY TRANSACTIONS
(2021)
Article
Mechanics
Fangrui Lv, Yanqin Shangguan, Donglin Zou, Aimin Ji
Summary: This study proposes a transient mixed-lubrication model considering turbulence to investigate the dynamic characteristics of mixed-lubricated bearings. The effects of turbulence, surface roughness, and impact load direction on transient lubrication are analyzed based on a derived transient Reynolds equation and the journal's dynamic equation.
Article
Engineering, Mechanical
Xun Huang, Ge Xu, Shuyun Jiang
Summary: This study proposes novel water-lubricated hydrodynamic spiral groove bearings for motorized spindles, and establishes a rotor-bearing static model for experimental research. The results show that these bearings have advantages in terms of low-temperature rise, good high-speed performance, and moderate spindle stiffness, and can be a potential alternative to fluid bearings for high-speed motorized spindles.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Acoustics
Thales Freitas Peixoto, Rainer Nordmann, Katia Lucchesi Cavalca
Summary: The use of turbocharger in downsized engines is common in various vehicle categories to reduce emissions. A dynamic model of the turbocharger rotor has been developed to analyze lateral and axial vibrations and bearing effects. Experimental and numerical results show good agreement in frequency domain and temperature estimates, especially at higher rotational speeds.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Engineering, Multidisciplinary
Yang Kang, Zizhen Qiu, Hao Zhang, Zhanqun Shi, Fengshou Gu
Summary: This study proposes a novel method for updating the finite element model of a rotor-discs system using measured modal parameters, which includes updating system mass and stiffness matrices through particle swarm optimization algorithm and determining a damping matrix based on experimental modal frequencies and damping ratios. The updated model shows higher accuracy in predicting frequency responses and identifying dynamic coefficients.
Article
Mathematics
Gerardo Amato, Roberto D'Amato, Alessandro Ruggiero
Summary: This paper proposes a new technique based on ANC-TC for stabilizing a flexible rotor shaft affected by self-generated sinusoidal disturbances. The theoretical investigation and numerical simulations demonstrate that the controller has good disturbance rejection capability and slightly different convergence speeds under different operating conditions.
Article
Engineering, Mechanical
Hao Zhang, Shuyun Jiang, Xiaohui Lin
Summary: This study investigates the effect of cavitation on the dynamic characteristics of high-speed water-lubricated journal bearings and develops a thermohydrodynamic cavitation lubrication model. Experimental results show that two secondary temperature peaks appear in the divergence zone of the bearing due to cavitation. Therefore, the cavitation effect should be considered when establishing the model for high-speed water-lubricated journal bearings, especially under a large eccentricity ratio.
TRIBOLOGY TRANSACTIONS
(2023)
Article
Engineering, Mechanical
Bassam J. Alshaer, Hamid M. Lankarani
Summary: A new solution for the dynamic characteristics of lubricated long journal bearing is derived by analytically integrating Reynold's equation. The solution does not involve approximations or assumptions and presents new equations to evaluate lubricant dynamic forces and zero pressure angles. The squeeze and dynamic effects are uncoupled, making it easier to study their contributions to total lubricant forces.
MECHANISM AND MACHINE THEORY
(2023)
Article
Engineering, Mechanical
Guo Xiang, Jiaxu Wang, Yanfeng Han, Tianyou Yang, Haiming Dai, Bowen Yao, Chuande Zhou, Liwu Wang
Summary: This study investigates the transient nonlinear dynamic behaviors of water-lubricated bearings with unbalanced rotors under mixed-TEHD condition. The thermal effect and friction force are found to play an important role in the nonlinear dynamic analysis. The perturbed method may lead to inaccurate predictions of transient hydrodynamic and contact forces, especially for the contact force, under mixed-TEHD condition. Parametric studies highlight the key factors for improving transient lubrication performance.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Physics, Multidisciplinary
Peng Li, Jiayu Li, Zhanqun Shi, Hao Zhang, Sen Xiao, Xin Li, Fengshou Gu
Summary: This study investigates the effects of manufacturing error and micro-groove on the static, dynamic, and stability characteristics of water-lubricated journal bearings. Mathematical models and simulations are used to evaluate the impact of these factors on the film thickness distribution, fluid pressure distribution, bearing capacity, and other parameters. The results show that manufacturing errors and micro-groove significantly affect the fluid film thickness and pressure distribution. The magnitude and type of errors can either improve or degrade the bearing performance, and micro-groove enhances the hydrodynamic effect in the bearing clearance.
