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Article
Publication date: 17 June 2022

Biao Li, Jun Sun, Hu Wang and Xiao Zhang

Under the action of many factors, the shaft of the shaft-journal bearing system inevitably moves along the axis direction at work, which will lead to the axial movement of…

Abstract

Purpose

Under the action of many factors, the shaft of the shaft-journal bearing system inevitably moves along the axis direction at work, which will lead to the axial movement of journal in the bearing. However, at present, only the dynamic and squeezing effects caused by the relative rotation and squeezing motion between the journal and the bearing surfaces are considered in the lubrication analysis of misaligned journal bearing and the axial movement of journal in the actual use of bearing is not considered. The purpose of this paper is to analyze the lubrication of journal bearing considering the axial movement of journal.

Design/methodology/approach

Taking the shaft-journal bearing system as the research object, a hydrodynamic lubrication model of journal bearing is established considering the axial movement and misalignment of journal. The finite difference method is used to solve the Reynolds equation for the lubrication analysis.

Findings

The axial movement of journal has a significant influence on the lubrication characteristics of misaligned journal bearing. The larger the misalignment angles of journal or the eccentricity of bearing, the greater the influence of the axial movement of journal on the lubrication performance of bearing. The lower the speed of bearing or the smaller the clearance of bearing, the more significant the influence of the axial movement of journal on the lubrication performance of bearing is.

Originality/value

The influence of the axial movement of journal on the lubrication performance of journal bearing is studied under different misalignment angles of journal, working conditions and clearances of bearing. The results of this paper are helpful to the design and research of the lubrication performance of journal bearing.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 9 February 2022

Haiming Dai, Guo Xiang, Jiaxu Wang, Juan Guo, Cheng Wang and Hang Jia

The purpose of this study is to numerically investigate the time-varying mixed lubrication performance of microgroove journal-thrust coupled bearing (MJTCB) under…

Abstract

Purpose

The purpose of this study is to numerically investigate the time-varying mixed lubrication performance of microgroove journal-thrust coupled bearing (MJTCB) under nonlinear excitation.

Design/methodology/approach

A three degree of freedom (3-DOF) dynamic model of the rotor coupling with the transient mixed lubrication behavior is established. Based on numerical predictions, the role of the microgroove on the time-varying mixed lubrication performance of MJTCB is identified. The effects of the microgroove depth, microgroove shape and external load on the time-varying mixed lubrication performance of MJTCB are also studied.

Findings

Numerical results show that the effect of the coupling hydrodynamic on the time-varying mixed lubrication performance of the coupled bearing is strengthen with the increasing of microgroove depth. Furthermore, it is found that the optimal microgroove shape for the thrust bearing, arc or rectangle, highly depends on the microgroove depth. Finally, the contact performance of the thrust bearing is slightly affected by the radial external load.

Originality/value

This study is expected to achieve a better understanding of the time-varying mixed lubrication performance of MJTCB under nonlinear excitations.

Details

Industrial Lubrication and Tribology, vol. 74 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 January 2022

Fangcheng Xu, Zeda Dong, Jianhua Chu, Haoming Wang and Yongliang Wang

Gas thrust foil bearings (GTFBs) are used to balance the axial load of engines. However, in some working conditions of large axial force, such as the use of single…

Abstract

Purpose

Gas thrust foil bearings (GTFBs) are used to balance the axial load of engines. However, in some working conditions of large axial force, such as the use of single impeller air compressor, the load capacity of GTFBs is still insufficient. To solve this problem, the load capacity can be improved by increasing the stiffness of bump foil. The purpose of this paper is to explore a scheme to effectively improve the performance of thrust foil bearings. In the paper, the stiffness of bump foil is improved by increasing the thickness of bump foil and using double-layer bump foil.

Design/methodology/approach

The foil deformation of GTFBs supported by three different types of bump foils, the relationship between friction power consumption and external force and the difference of limited load capacity were measured by experimental method.

Findings

The variation of the foil deformation, bearing stiffness, friction power consumption with the external force at different speeds and limited load capacity are obtained. Based on experimental results, the selection scheme of bump foil thickness is obtained.

Originality/value

This paper provides a feasible method for the performance optimization of GTFBs.

Details

Industrial Lubrication and Tribology, vol. 74 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 28 August 2021

Xingxin Liang and Zhiyong Yang

This paper aims to confirm that increasing the hardness of thrust collars can improve the load carrying capacity (LCC) and wear resistance of water lubricated thrust…

Abstract

Purpose

This paper aims to confirm that increasing the hardness of thrust collars can improve the load carrying capacity (LCC) and wear resistance of water lubricated thrust bearings (WTBs) made of polymers paired with non-polymeric thrust collars, and to design a WTB with high LCC and durability for a shaftless pump-jet propulsor of an autonomous underwater vehicle. Six kinds of WTBs were manufactured by matching aluminum bronze, stainless steel and silicon nitride with two different polymer bearing materials. Their tribological behaviors were tested and compared.

Design/methodology/approach

The tribological behaviors of the WTBs made with different materials were investigated experimentally on a specially designed test rig.

Findings

Aluminum bronze is not suitable for crafting thrust collars of heavy load WTBs due to severe abrasive wear. Two body abrasive wear first occurred between the thrust collar and the polymer bearing. Next, aluminum bronze wear particles were produced. The particles acted between the two materials and formed three body abrasive wear. Stainless steel/polymer bearings showed better wear resistance while Si3N4/polymer bearings were the best. Improving the hardness of thrust collars is significant to the LCC and service life of WTBs.

Originality/value

The wear mechanism of WTBs under heavy load conditions was revealed. Improving the hardness of the thrust collar was confirmed to be a preferable method to improve the wear resistance and LCC of WTBs. The results of this study may provide an important reference for the selection of water lubricated materials and the design of heavy load WTBs.

Details

Industrial Lubrication and Tribology, vol. 73 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 7 August 2021

Abdelaziz Khennouf and Mohamed Baheddi

The estimation of bearing capacity for shallow foundations in swelling soil is an important and complex context. The complexity is due to the unsaturated swelling soil…

Abstract

Purpose

The estimation of bearing capacity for shallow foundations in swelling soil is an important and complex context. The complexity is due to the unsaturated swelling soil related to the drying and humidification environment. Hence, a serious study is needed to evaluate the effect of swelling potential soil on the foundation bearing capacity. The purpose of this paper is to analyze the bearing capacity of a rough square foundation founded on a homogeneous swelling soil mass, subjected to vertical loads.

Design/methodology/approach

A proposed numerical model based on the simulation of the swelling pressure in the initial state, followed by an elastoplastic behavior model may be used to calculate the foundation bearing capacity. The analyses were carried out using the finite-difference software (FLAC 3 D) with an elastic perfectly plastic Mohr–Coulomb constitutive model. Moreover, the numerical results obtained are compared with the analytical solutions proposed in the literature.

Findings

The numerical results were in good agreement with the analytical solutions proposed in the literature. Also, reasonable capacity and performance of the proposed numerical model.

Originality/value

The proposed numerical model is capable to predict the bearing capacity of the homogeneous swelling soil mass loaded by a shallow foundation. Also, it will be of great use for geotechnical engineers and researchers in the field.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 7 June 2022

Nayab Rasool Syed and Sashindra Kumar Kakoty

The purpose of this paper is to compare the spherical protruded and dimple textured journal bearings performance characteristics with the untextured bearing.

Abstract

Purpose

The purpose of this paper is to compare the spherical protruded and dimple textured journal bearings performance characteristics with the untextured bearing.

Design/methodology/approach

The governing Reynolds equation considering the mass conserving (JFO) boundary conditions is solved using the computationally efficient progressive mesh densification (PMD) method. The central difference scheme is used for the discretization of the governing Reynolds equation. The numerical code developed is validated with the experimental results available in the literature.

Findings

From this numerical study, it has been observed that the protruded textured journal bearing gives better performance compared to the dimple textured and untextured journal bearing for friction variable, whereas dimple textured journal bearing provides better performance compared to the protruded textured and untextured journal bearing for load carrying capacity and flow coefficient. For better performance, dimple and protruded textured bearings must be textured in second-half textured region configuration.

Practical implications

The results shown here would be quite useful for the researchers generally and the bearing designers particularly.

Originality/value

The load carrying capacity should be maximum whereas, the friction coefficient should be minimum and also the adequate flow of lubricant is necessary to maintain hydrodynamic lubrication and to remove the heat generated within the bearing due to friction, which impacts the bearing performance and life. Thus, this study would be significant in effective bearing design aspect.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 June 2022

Cuicui Chen, Qian Yang, Qingan Chen, Yanhui Wang, Dong Xu, Hezong Li, Xiliang Zhang, Christopher M. Harvey and Jiwei Liu

This study aims to investigate the effects of graphite-MoS2 composite solid lubricant on the tribological properties of copper-based bearing materials under dry conditions.

Abstract

Purpose

This study aims to investigate the effects of graphite-MoS2 composite solid lubricant on the tribological properties of copper-based bearing materials under dry conditions.

Design/methodology/approach

The mixture of Graphite-MoS2 was inlaid in ZQSn6-6–3 tin bronze and ZQAl9-4 aluminum bronze matrix. These copper-embedded self-lubricating bearing materials were considered in friction pairs with 2Cr13 stainless steel, and their tribological properties were studied by using an MM200 wear test machine.

Findings

The results show that the friction coefficients and wear rates of copper-embedded self-lubricating bearing materials are lower than those of the ordinary copper-based bearing materials. The wear performance of the tin bronze inlaid self-lubricating bearing material is better than that of the aluminum bronze inlaid self-lubricating bearing material. The wear mechanism of the tin bronze bearing material is mainly adhesive wear, and that of the aluminum bronze bearing material is mainly grinding wear, oxidation wear and adhesive wear. The copper-embedded self-lubricating bearing materials had no obvious abrasion, whereas the aluminum bronze inlaid self-lubricating bearing material exhibited deep furrows and obvious abrasion under high loads.

Originality/value

These results are helpful for the application of copper-embedded self-lubricating bearing materials.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 12 November 2020

Liangliang Li and Yonghui Xie

Owing to the development of the smaller-sized rotational machinery, the demand for the high-speed and low-resistance gas bearing increases rapidly. The research of micro…

Abstract

Purpose

Owing to the development of the smaller-sized rotational machinery, the demand for the high-speed and low-resistance gas bearing increases rapidly. The research of micro gas bearing in the condition of rarefied gas state is still not satisfied. Therefore, the purpose of this paper is to present a numerical investigation of the effect of misalignment and rarefaction effect on the comprehensive performance of micro-electrical-mechanical system (MEMS) gas bearing.

Design/methodology/approach

The Fukui and Kaneko model is expanded to 2D solution domain to describe the flow field parameters. The finite element method is used to discretize the equation. Newton–Raphson method is used to solve the nonlinear equations for the static performance of gas bearing, and partial deviation method is adopted for the solution of dynamic equations.

Findings

The static and dynamic characteristics of MEMS gas bearing are calculated, and the comparison is made to study the influence of rarefaction effect and misalignment. The results show that the rarefaction effect will decrease bearing load capacity compared with traditional solution of Reynolds equation, and the misalignment will reduce the stability of bearing. The influence of misalignment on gas film thickness is also analyzed in this paper.

Originality/value

The investigation of this paper emerges the change regularity of comprehensive performance of MEMS gas bearing considering rarefaction effect and misalignment, which provides a reference for the actual manufacturing of MEMS gas bearing and for the safety operation of micro dynamic machinery.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0023/

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 7 May 2021

Lili Wang, Mengxue He, Min Wang and Yuliang Wei

Under the influence of loading, manufacturing, installation and other factors, the axis of sleeve bearing and journal will not be aligned, which will have a great impact…

Abstract

Purpose

Under the influence of loading, manufacturing, installation and other factors, the axis of sleeve bearing and journal will not be aligned, which will have a great impact on running stability and life of bearing. The existence of oil groove can effectively improve the life of sleeve bearing and working efficiency. The lubrication performance of two and three grooves sleeve bearing considering journal misalignment is analyzed.

Design/methodology/approach

To solve the difference of discontinuous position of oil film thickness, it is necessary to use the flow balance relationship in the finite control space, and oil film thickness equation of multi-groove sleeve bearing considering journal misalignment is gained.

Findings

The friction and bearing capacity of journal bearing with oil groove increase with the increase of journal inclination angle. At the same journal inclination angle, the bearing capacity of two-axial groove journal bearing is larger than that of three-axial groove journal bearing, but the friction of two-axial groove journal bearing shows the trend of the first bigger and then smaller than that of three-axial groove journal bearing.

Originality/value

The research has great significance to optimize bearing lubrication performance and increase bearing working life.

Details

Industrial Lubrication and Tribology, vol. 73 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 9 December 2020

Shengtong Wang, Ouyang Wu, Zhe Li and Bin Wang

Proposing a new type of water-lubricated thrust bearing meets the load-bearing requirements of high-power shaft-less rim driven thrusters.

Abstract

Purpose

Proposing a new type of water-lubricated thrust bearing meets the load-bearing requirements of high-power shaft-less rim driven thrusters.

Design/methodology/approach

The designs were tested by establishing a bearing thermal-fluid-magnetic comprehensive simulation model and developing bearing fluid film force and magnetic simulation. Lubrication performance tests were carried out on the bearing test rig.

Findings

The Halbach array of magnet blocks is able to reach the maximum magnetic force. The material of sheath can help increase the magnetism. The magnetism is able to reduce wear during low-speed and the start-stop phase, while the eddy current loss at high speeds will lead to a decrease in magnetic force. The experiment found that the bearing was more stable at low speeds and would not demagnetize due to the temperature rise, but it is necessary to pay attention to the running stability at high speeds to prevent rubbing and impact.

Originality/value

An innovative combination of hydrodynamic pressure and permanent magnetic repulsion was observed to form a magnetic-liquid double suspension bearing with large bearing capacity.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0295

Details

Industrial Lubrication and Tribology, vol. 73 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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