Xiuli Zhang, Wenkai Gao, Jian Cui, Yuankang Shen, Tao Huang, Gengyuan Gao and Jun Cao
Rubber-plastic double-layer bush water-lubricated bearings have demonstrated superior performance, while research on their vibration characteristics remains limited. This paper…
Abstract
Purpose
Rubber-plastic double-layer bush water-lubricated bearings have demonstrated superior performance, while research on their vibration characteristics remains limited. This paper aims to investigate the lubrication and vibration properties of these bearings by experiments and examine the effect of rubber-to-plastic bush thickness ratio on bearing performance.
Design/methodology/approach
A water-lubricated journal bearing test rig is constructed, and three bearings with different bush thickness ratios are fabricated. Bush deformation under various loads is measured, and the friction coefficient and axis trajectory under different operating conditions are tested. The vibration responses of the bearings under directional harmonic excitation are studied. The influences of rotational speed, load and rubber-to-plastic bush thickness ratio on the bearing’s lubrication and vibration properties are analyzed.
Findings
The friction coefficient of the bearing initially decreases rapidly and subsequently increases gradually as the rotational speed or load increases. The bearing with a thicker rubber bush shows lower displacement amplitudes in its axis trajectory. Under a 45° directed excitation, significant oscillations are observed in the vertical displacement, while the horizontal displacement remains stable. The damping effect of the bearing with a thicker rubber bush is more pronounced.
Originality/value
This paper present the influence of rubber-to-plastic bush thickness ratio on bearing lubrication and vibration performance. The results are valuable for the design of this type of bearing.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2024-0469/
Details
Keywords
Yanzhen Wang, Zhongwei Yin, Dan Jiang, Gengyuan Gao and Xiuli Zhang
Water lubrication is significant for its environmental friendliness. Composite journal bearing is liable to deform for the huge pressure of water film. This paper aims to study…
Abstract
Purpose
Water lubrication is significant for its environmental friendliness. Composite journal bearing is liable to deform for the huge pressure of water film. This paper aims to study the influence of elastic deformation on how lubrication functions in water-lubricated journal bearings and to provide references for designing composite journal bearings.
Design/methodology/approach
The combination of computational fluid dynamics and fluid-structure interaction is adopted in this paper to study the lubrication performance of water-lubricated compliant journal bearings. The influences of elasticity modulus and Poisson’s ratio on load-carrying capacity and elastic deformation are studied for different rotational speeds. Predictions in this work are compared with the published experimental results, and the present work agrees well with the experimental results.
Findings
A reference whether elastic deformation should be considered for composite journal bearings is proposed under different working conditions. Besides, a reference to determine water-lubricated plain journal bearings dimensions under different loads and rotational speeds is developed with the effect of both elastic deformation and cavitation being accounted.
Originality/value
The present research provides references as to whether elastic deformation should be considered in operation and to determine compliant journal bearings’ dimensions in the design process.
Details
Keywords
Jun Cao, Zhongwei Yin, Yuqing Cui, Hulin Li, Gengyuan Gao and Xinbo Wang
The purpose of this study was to solve the problem of most woven-fabric self-lubricating bearings that find it difficult to function at temperatures above 320°C, by designing a…
Abstract
Purpose
The purpose of this study was to solve the problem of most woven-fabric self-lubricating bearings that find it difficult to function at temperatures above 320°C, by designing a new type of new nuclear joint bearing. The results of this study will help designers to achieve accurate stress distribution, displacement deformation, fatigue life and damage of bearings. All of these can be a guide for designing self-lubricating joint bearings.
Design/methodology/approach
Finite element analysis is undertaken to simulate the new design bearings. To get the most appropriate and accurate results, the room temperature simulation (Simulation A), the modulus of elasticity that changes with temperature (Simulation B) and the thermal-structure-coupled simulation (Simulation C) are compared. The fatigue simulation is conducted to verify whether the self-lubricating method is reasonable and whether the bearing can function for over 60 years in an enclosed environment.
Findings
Stress distribution and displacement deformation of joint bearing can be accurately achieved via the thermal-structure coupled simulation. Work life and damage results have been achieved via the fatigue analysis, and the suggested working loads can be calculated via safety factors.
Originality/value
The newly designed joint bearing in which the graphite is laid on the outside of the inner ring functions and self-lubricates at temperatures above 320°C.
Details
Keywords
Xinbo Wang, Zhongwei Yin, Hulin Li, Gengyuan Gao and Jun Cao
The purpose of this paper is to study the frictional behaviors of CuAl10Fe3 journal bearings sliding against chromium electroplated 42CrMo shafts and diamond-like carbon-coated…
Abstract
Purpose
The purpose of this paper is to study the frictional behaviors of CuAl10Fe3 journal bearings sliding against chromium electroplated 42CrMo shafts and diamond-like carbon-coated 42CrMo shafts, respectively, under two different conditions and to compare the two kinds of friction pairs.
Design/methodology/approach
All journal bearing samples underwent 24 h running-in and repeatability verification. Then, the journal bearing friction experiments were carried out under two different conditions. After testing, the torques, friction coefficients, power consumptions and other parameters were obtained.
Findings
The pair of CuAl10Fe3 journal bearing and diamond-like carbon–coated shaft could drive greater load to start up than the pair of CuAl10Fe3 journal bearing and chromium electroplated 42CrMo shaft, but it had greater power consumption during the steady running period under the identical condition. With the changing of specific pressure or rotational speed, the friction coefficients had different variations. The frictional oscillations appeared at 32 rotations per minute under heavy loads for both kinds of pairs, the oscillation frequencies were equal to rotational frequency of the test shaft and the oscillation amplitude for diamond-like carbon coating was much greater.
Originality/value
These results have guiding significance for practical industrial applications.
Details
Keywords
Gao Gengyuan, Yin Zhongwei, Jiang Dan and Zhang Xiuli
The purpose of this paper is to improve hydrodynamic load-carrying capacity of a water-lubricated journal bearing by a new bush structure. Water-lubricated bearing is becoming…
Abstract
Purpose
The purpose of this paper is to improve hydrodynamic load-carrying capacity of a water-lubricated journal bearing by a new bush structure. Water-lubricated bearing is becoming more and more popular since it is environmentally friendly and saves energy. However, contrary to oil and grease-lubricated bearings, water-lubricated bearing is limited in many situations due to its low hydrodynamic load-carrying capacity.
Design/methodology/approach
The present article proposes a new bearing bush, with a transition-arc structure, which is favorable for increasing hydrodynamic load-carrying capacity. Hydrodynamic load-carrying capacity was calculated by means of three-dimensional computational fluid dynamics (3-D CFD) analysis. Several variants of a journal bearing with a transition-arc structure of different dimensions are analyzed, while the radial clearance of the bearing, eccentricity ratio and the velocity of the journal remain unchanged.
Findings
The results show that obvious changes are found in hydrodynamic load-carrying capacity of a water-lubricated journal bearing. For different width over diameter (L/D) bearing ratios, the relationship between hydrodynamic load-carrying capacity and the magnitude of the transition-arc structure dimension is researched.
Originality/value
The research presented here leads to a design reference guideline that could be used by the designer engineer to design smart journal bearings for improving the hydrodynamic load-carrying capacity.
Details
Keywords
Lili Wang, Qingliang Zeng, Changhou Lu and Peng Liang
This paper aims to reveal the cavitation characteristics of three oil wedges sleeve bearing and set the theoretical and experimental basis for defining the oil film boundary…
Abstract
Purpose
This paper aims to reveal the cavitation characteristics of three oil wedges sleeve bearing and set the theoretical and experimental basis for defining the oil film boundary condition.
Design/methodology/approach
Computational fluid dynamics model of three oil wedges sleeve bearings based on the Navier–Stokes equation is set using Fluent considering turbulent situation and two-phase flow theory. The cavitation characteristics of bearing is investigated by taking pictures of experiment.
Findings
The rupture region of oil film and the contours of air volume fraction increase distinctly with the increase of rotating speed and the decrease of input pressure. The critical rotating speed of cavitation occurrence and oil film pressure increases with the increase of input pressure. The change trend of experiment cavitation with the rotating speed and input pressure is consistent with theoretical cavitation in general.
Originality/value
The finite element model of three oil wedges sleeve bearings is established based on the Navier-Stokes calculation equation of the fluid, two-phase flow theory and turbulent model. Sleeve bearing is transparent, the pictures of cavitation can be easily taken by high-speed camera, the cavitation characteristics of bearing is studied by experiment. The cavitation performance of three oil wedges bearings is studied with the change of input pressure and rotating speed, the change trend is basically consistent for theory and experiment. The study on critical rotating speed of cavitation occurrence is benefit for defining the oil film boundary condition.