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Article
Publication date: 1 March 2024

Jun Cheng and Chunxing Gu

As the crucial support component of the propeller power system, the reliability of the operation of submersible pumps is influenced by the lubrication performance of…

Abstract

Purpose

As the crucial support component of the propeller power system, the reliability of the operation of submersible pumps is influenced by the lubrication performance of water-lubricated thrust bearings. When the water-lubricated thrust bearings are under start-stop or heavy load conditions, the effect of surface morphology is crucial as the mixed lubrication regime is encountered. This paper aims to develop one mixed lubrication model for the water-lubricated thrust bearings to predict the effects of surface skewness, kurtosis and roughness orientation on the loading carrying capacity and tribological behavior.

Design/methodology/approach

This paper developed one improved mixed lubrication model specifically for the water-lubricated thrust bearing system. In this model, the hydrodynamic model was improved by using the height of the rough surface and its probability density function, combined with the average flow model. The asperity contact model was improved by using the equation for the Pearson system of frequency curves to characterize the non-Gaussian aspect of surface roughness distribution.

Findings

According to the results, negative skewness, large kurtosis and lateral surface pattern can improve the tribological performance of water-lubricated thrust bearings. Optimizing the surface morphology is a reasonable design method that can improve the performance of water-lubricated thrust bearings.

Originality/value

In this paper, one mixed lubrication model specifically for the water-lubricated thrust bearing with the effect of surface roughness into consideration was developed. Based on the developed model, the effect of surface morphology on tribological behavior can be evaluated.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0247/

Details

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

Keywords

Article
Publication date: 2 March 2020

Zhiming Zhao and Rui Zhang

The hydrodynamic characteristics of liquid film for bearings, especially water-lubricated bearings with a large length-to-diameter ratio, affect the dynamics behavior of rotor…

Abstract

Purpose

The hydrodynamic characteristics of liquid film for bearings, especially water-lubricated bearings with a large length-to-diameter ratio, affect the dynamics behavior of rotor bearing systems. The purpose of this study is to carry out theoretical analysis and experiments to determine the hydrodynamic characteristics of water-lubricated journal bearings.

Design/methodology/approach

The finite difference method is adopted for the simulation of the characteristics of water-lubricated bearings. The comparison results between water-lubricated bearings with and without grooves, as well as with and without the consideration of the effects of rubber deformation, are presented. The test bearings, test bench, and monitoring system, especially the force exciter for the bearing experiment, are presented. Dynamic coefficient identification verification experiments were performed in different working situations. The obtained results include the calibration of magnetic force, two kinds of excitation, vibration data of the rotor system and dynamic coefficients.

Findings

The theoretical results demonstrate that the hydrodynamic effect was obvious when the speed was increased and that the water film had improved capability at a working speed of 1800 rpm. The identification results reveal the lubrication situation of the test bearing under low-speed and high-load conditions. Moreover, it was found that the liquid film was not continuous at low speeds.

Originality/value

The theoretical results can lead to the enhancement of the design level of water-lubricated rubber journal bearings with a large aspect ratio. The experimental results can lead to the improvement of the dynamic behavior design of rotor systems supported using water-lubricated bearings with a large length-to-diameter ratio.

Details

Industrial Lubrication and Tribology, vol. 72 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 January 2022

Liwu Wang, Yanfeng Han, Dongxing Tang and Jianlin Cai

The purpose of this paper is to verify the effectiveness of the proposed transient mixed lubrication and wear coupling model [mixed lubrication and wear (MLW) coupling model…

Abstract

Purpose

The purpose of this paper is to verify the effectiveness of the proposed transient mixed lubrication and wear coupling model [mixed lubrication and wear (MLW) coupling model] under water lubricated conditions by comparing with the experimental results.

Design/methodology/approach

Water lubricated bearings are the key parts of the transmission system of an underwater vehicle and some surface ships. In this study, the friction and wear behaviors of rubber, nylon and polyether ether ketone (PEEK) samples with stainless steel underwater lubrication were compared by using ring-block contact structure on multifunctional friction and wear test bench-5000 friction and wear tester.

Findings

The results show that the transient wear depth and wear amount of PEEK, nylon and rubber samples under water lubrication are in good agreement with the calculated results of the theoretical model, which verifies the rationality and scientific nature of the MLW coupling model. Thus, the numerical model is applicable for the wear prediction of the journal bearing under water-lubricated conditions. Furthermore, numerical and experimental results reveal that the anti-wear performance among three water-lubricated materials can be ranked by: PEEK > nylon > rubber.

Originality/value

It is expected that this study can provide more information for experimental and numerical research of water-lubricated bearings under water-lubricated conditions.

Details

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

Keywords

Article
Publication date: 4 March 2014

You-Qiang Wang, Xiu-Jiang Shi and Li-Jing Zhang

Water-lubricated rubber bearing is one of the most appropriate bearings for underwater use. The most popular design used widely today is the straight fluted rubber bearing. The…

Abstract

Purpose

Water-lubricated rubber bearing is one of the most appropriate bearings for underwater use. The most popular design used widely today is the straight fluted rubber bearing. The special configuration leads to partial hydrodynamic lubrication and low load capacity. A new bearing bush structure with two cavities which is favorable for constructing continuous hydrodynamic lubrication was designed and studied. The paper aims to discuss these issues.

Design/methodology/approach

A new bearing bush structure with two cavities which is favorable for constructing continuous hydrodynamic lubrication was designed. The apparatus for studying the tribological behaviors of the two types of water-lubricated rubber bearings has been devised and established in the paper. The experimental studies on the tribological properties of the rubber bearings have been conducted under different loads and velocities. The eccentricity ratio of the new structure rubber bearing with two cavities was measured in experiment and the load capacity was calculated by numerical simulation.

Findings

The experimental results show that the friction coefficient decreases with increasing velocity; the friction coefficient increases sharply with the rising temperature, the friction coefficient increases at first and then decreases with increasing load for fluted rubber bearings. The numerical results were in good agreement with the experimental results. The numerical results show that complete hydrodynamic lubrication can be formed in the new designed rubber bearing with two cavities. The experimental and numerical results all indicate that there is an appropriate bearing clearance which the friction coefficient is minimum and the load capacity is maximum.

Originality/value

A new bearing bush structure with two cavities which is beneficial to constructing continuous hydrodynamic lubrication film was designed. A new apparatus for studying the tribological behaviors of the two types of water-lubricated rubber bearings has been devised and established. Experimental and numerical study on the new structure rubber bearing were conducted in the paper.

Details

Industrial Lubrication and Tribology, vol. 66 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 9 February 2015

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

Industrial Lubrication and Tribology, vol. 67 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 August 2018

Chuang Wang, Ziwen Xing, Xi Pan and Zhilong He

The well-operating condition of journal bearing is the assurance to keep superior performance of water-lubricated twin-screw compressor. To design the journal bearing more…

Abstract

Purpose

The well-operating condition of journal bearing is the assurance to keep superior performance of water-lubricated twin-screw compressor. To design the journal bearing more reasonably for this type of compressor, this paper aims to study the effects of rotating speed and design parameters on bearing characteristics, considering surface roughness and bending deformation of the shaft at the same time.

Design/methodology/approach

The average Reynolds equation considering the effect of surface roughness is adopted and solved by finite difference method and successive over-relaxation method to calculate pressure distribution with real bearing shapes and boundary conditions. The bending deformation of the shaft is calculated using simply supported beam model of variable cross-section.

Findings

The dynamic lubrication characteristics of four water-lubricated journal bearings in twin-screw air compressor are calculated and analyzed. In addition, the static characteristics of journal bearing including friction coefficient, film thickness ratio distribution and water film pressure distribution are calculated numerically with different rotating speed and design parameters. Moreover, some design principles of water-lubricated bearing for twin-screw compressor are put forward.

Originality/value

The lubrication characteristics of the water-lubricated journal bearing in twin-screw air compressor are calculated considering surface roughness and bending deformation of the shaft at the same time. The paper’s results may provide design guidelines for journal bearing in this kind of twin-screw compressor.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 20 October 2020

Bin Xiao, Xiaolin Zheng, Yi Zhou, Dan Yao and Yang Wan

This study aims to evaluate the tribological behavior of water-lubricated rubber bearings sliding against stainless steel under different lubricate conditions.

Abstract

Purpose

This study aims to evaluate the tribological behavior of water-lubricated rubber bearings sliding against stainless steel under different lubricate conditions.

Design/methodology/approach

The water-lubricated rubber bearings under various normal loads and sliding speeds were carried out on the ring-block friction test, and the wear morphology is test conducted by using scanning electron microscope.

Findings

The results indicate that the surface of water-lubricated rubber bearings has a more alternative friction coefficient and wear rate under seawater than other lubricate conditions. The seawater not only acts as a lubricating medium but also brings microstructure while corroding the rubber interface, thereby further enhancing the lubricating effect and storing abrasive debris.

Originality/value

In this paper, tribological properties of the water-lubricated rubber bearing on ring-block friction test has been investigated. Water-lubricated rubber bearing was carried out on various lubricate conditions, and the friction coefficient, wear rate and worn surface were analyzed. Also, the effects of sliding speeds were investigated.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0204/

Details

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

Keywords

Article
Publication date: 8 June 2015

Nan Wang and Qingfeng Meng

The purpose of this paper is to provide a nondestructive monitoring method based on wireless sensor technology to measure the continuous circumferential film pressure on radial…

Abstract

Purpose

The purpose of this paper is to provide a nondestructive monitoring method based on wireless sensor technology to measure the continuous circumferential film pressure on radial cross-section of water-lubricated bearing, in addition, to study the influence factors to wireless communication.

Design/methodology/approach

The unique shaft and wireless equipments are designed, the pressure sensors are installed in right shoulder of shaft, the wireless transmitter is installed at the end of shaft and the sensors are connected with wireless transmitter by data cable. By this way, the film pressure can be obtained via wireless communication. The film pressure of eight grooved water-lubricated rubber bearings with concave staves is measured, the performance evaluation of wireless equipments is conducted and the influence factors to wireless communication is analyzed by Doppler frequency shift theory.

Findings

The rupturing and nonuniform water film is observed, the grooves decrease the film pressure of rubber bearing which is in mixed lubricating state. The main influence factor to wireless communication is shaft speed which has greater effect on packet loss rate than that on bit error rate.

Practical implications

By studying the actual continuous water film pressure, the bearing properties can be studied in-depth, and this has significant meaning to the design and application of bearing. Moreover, the study on influence factors to wireless communication can be used for references to other wireless monitoring on rotating machinery.

Originality/value

The continuous water film pressure can be monitored by this method, the lubricating state of bearing working surface cannot be damaged and the signal attenuation can be avoided. Therefore, the measuring accuracy is promoted and the measuring process also becomes convenient and high efficiency.

Details

Industrial Lubrication and Tribology, vol. 67 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 August 2022

Juan Guo, Yanfeng Han, Shouan Chen, Jianlin Cai and Haiming Dai

This paper aims to identify the role of the wall slip on the dynamic characteristics of the multi-groove water-lubricated bearing considering rough contact, including stiffness…

Abstract

Purpose

This paper aims to identify the role of the wall slip on the dynamic characteristics of the multi-groove water-lubricated bearing considering rough contact, including stiffness and damping coefficients of the water film and contact stiffness coefficient of the asperity contact.

Design/methodology/approach

The modified perturbed average Reynolds equations with the wall slip are derived, and the calculated perturbed hydrodynamic pressures are integrated to obtain the stiffness and damping coefficients of the water film. The elastic-plastic contact model of Kogut and Etsion is used to determine the contact stiffness coefficient.

Findings

Numerical results reveal that the wall slip has the more significant impact on the water film stiffness coefficients compared with the damping and contact stiffness coefficients. When the slip angle lies in a reasonable range, the lubrication performance can be effectively improved, especially in the mixed lubrication condition. In addition, it is worth emphasizing that the abrupt change of the water film stiffness coefficients occurs at the region II (pressure zone) in this study.

Originality/value

The influence mechanism of the wall slip on the dynamic characteristics of the water-lubricated bearing considering rough contact is first revealed.

Details

Industrial Lubrication and Tribology, vol. 74 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 April 2016

Zhongliang Xie, Zhu-shi Rao, Na Ta and Ling Liu

This paper aims to provide efficient methods to calculate the friction coefficients and film thickness ratios in mixed lubrication (ML) regime for water lubricated bearings

Abstract

Purpose

This paper aims to provide efficient methods to calculate the friction coefficients and film thickness ratios in mixed lubrication (ML) regime for water lubricated bearings. Mathematical models consider influence of micro-asperities contacts which is based on the Gauss random distribution.

Design/methodology/approach

Effects of external loads, rotating speeds and radial clearances are obtained. Algorithm shown here is applied to a class of common industrial problems. Calculated Stribeck values are given and evaluated. The calculated and experimental results agree well which proves the correctness of the model.

Findings

In Part I, the authors believe that the paper presents the following for the first time: universal methods are developed for the calculation of friction coefficients and film thickness ratios (lambda) in ML regime; effects of different external loads, rotating speeds and radial clearances on friction coefficients and film thickness ratios are presented in detail; comparisons are made between the results predicted by the model and experimental results, and they agree rather well which proves the correctness of the model.

Originality/value

Present work successfully develops universal methods for predicting the friction coefficients and film thickness ratios.

Details

Industrial Lubrication and Tribology, vol. 68 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 178