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Article
Publication date: 13 April 2015

Ji Bin Hu, Chao Wei and XueYuan Li

– The purpose of this paper is to investigate the friction and sealing characteristics of narrow end face seal ring with spiral grooves for wet clutch by experiment.

Abstract

Purpose

The purpose of this paper is to investigate the friction and sealing characteristics of narrow end face seal ring with spiral grooves for wet clutch by experiment.

Design/methodology/approach

The shallow spiral grooves are machined in the end face of narrow seal ring by laser, and all of other parameters of specimens are the same with the actual production. The investigation of friction and sealing characteristics are carried out by comparing the experiment results of end face seal ring with spiral grooves with the conventional seal ring without spiral grooves through friction coefficient test, volume leakage rate test and pv value test.

Findings

Comparing with conventional seal ring without spiral grooves, seal ring with spiral grooves experiences boundary lubrication, mixed lubrication and fluid film lubrication with the increase of rotation speed, whereas the conventional seal ring only experiences mixed lubrication. Besides this, the volume leakage rate is slightly larger, but the pv value is much larger than that of conventional seal ring.

Originality/value

Effect of spiral grooves on the friction and sealing characteristics of narrow end face seal ring for wet clutch is investigated. The improved lubrication performance can be achieved by shallow spiral grooves even if the distance of radius difference used to machine grooves is very small.

Details

Industrial Lubrication and Tribology, vol. 67 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 September 2020

Delei Zhu and Shaoxian Bai

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO2 (S-CO2

Abstract

Purpose

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO2 (S-CO2) spiral groove face seals in the supercritical regime.

Design/methodology/approach

The spiral groove face seal was used as the research object. The distribution of lubricating film pressure and temperature was analysed by solving the gas state, Reynolds and energy equations using the finite difference method. Furthermore, the influence law of sealing performance was obtained.

Findings

Close to the critical temperature of S-CO2, face distortions produced by increasing pressure lead to divergent clearance and resulted in reduced opening force. In the state of S-CO2, the face distortions generated by increasing seal temperature lead to convergent clearance, which enhances the opening force. In addition, near the critical temperature of S-CO2, the opening force may be reduced by 10%, and the leakage rate of the seal sharply increases by a factor of four.

Originality/value

The thermoelastohydrodynamic characteristics of supercritical CO2 face seals are illustrated considering the actual gas effect including compressibility, heat capacity and viscosity. Face distortions and sealing performance were calculated under different seal pressures and seal temperatures in the supercritical regime, as well as with N2 for comparison.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0169/

Details

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

Keywords

Article
Publication date: 4 March 2014

Zhang Guo-yuan, Wei-gang Zhao and Yan Xiu Tian

A new type of hydrostatic and hydrodynamic non-contacting face seals has been designed to meet the requirements of lower leakage, longer life and more repeatedly start and stop on…

Abstract

Purpose

A new type of hydrostatic and hydrodynamic non-contacting face seals has been designed to meet the requirements of lower leakage, longer life and more repeatedly start and stop on shaft seals raised by liquid rocket engine turbopumps. And an experimental study on the performance of the face seal in the actual liquid oxygen turbopump was completed where low-viscosity water was selected as the seal fluid for the sake of safety. The paper aims to discuss these issues.

Design/methodology/approach

Different performances of face seals under preset conditions were obtained by repeatedly running tests, and the main performance parameters encompass leakage, fluid film pressure between the faces, operating power, face temperature, and so on.

Findings

The results indicate that the designed face seal has a smaller amount of leakage, with a minimum value of 3 ml/s. Furthermore, the designed face seal has been proved to demand lower operating power. Since its operating power changes slightly with different sealed fluid pressures, the new seal can be deployed in the harsh working condition with high pressure or with high speed (greater than 20,000 rpm). However, one proviso is that when liquid is employed as the seal fluid, the groove depth should be relatively deeper (greater than 10 μm).

Research limitations/implications

In response to future engineering requirements, study on the controllable spiral-groove face seals to improve the current design is being conducted.

Originality/value

The advancement of such non-contacting face seals proffers important insights to the design of turbo-pump shaft seal in a new generation of liquid rocket engine with regard to the requirement of frequent start and stop as well as long life on it.

Details

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

Keywords

Article
Publication date: 14 June 2023

Penggao Zhang, Fei Feng, Xiu Feng and Long Wei

Magnetic fluid has excellent function used as lubricants in bearings and mechanical seals, and the purpose of this study is to investigate the sealing performance in a spiral

Abstract

Purpose

Magnetic fluid has excellent function used as lubricants in bearings and mechanical seals, and the purpose of this study is to investigate the sealing performance in a spiral groove mechanical seal lubricated by magnetic fluid.

Design/methodology/approach

The sealing characteristic parameters of the lubricating film between the end faces of two sealing rings were calculated based on the Muijderman narrow groove theory for a spiral groove mechanical seal lubricated by magnetic fluid. The film thickness was determined according to the balanced forces on the rotating ring, and the effects of operating conditions, intensity of the magnetic field and diameter of nanoparticles on the sealing characteristics were investigated.

Findings

It has been found that the intensity of magnetic field has a great effect on the viscosity of magnetic fluid, film thickness and friction torque while has a little effect on the mass flux of magnetic fluid. The film thickness, mass flux of magnetic fluid and friction torque increase with the increasing volume fraction, rotating speed and diameter of magnetic nanoparticles in magnetic fluid. The mass flux of magnetic fluid decrease with the increasing closing force, and the friction torque decreases with the increase of media pressure.

Originality/value

The change of intensity of magnetic field can affect the viscosity of magnetic fluid and then changes the sealing performance in a mechanical seal lubricated by magnetic fluid. To reduce the mass flux of magnetic fluid and friction torque, the volume fraction, diameter of solid magnetic particles and film thickness should be 5%–7%, 8–10 nm and 2–9.3 µm, respectively.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2023-0032/

Details

Industrial Lubrication and Tribology, vol. 75 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 October 2018

Penggao Zhang, Boqin Gu, Jianfeng Zhou and Long Wei

The purpose of this study is to investigate the hydrodynamic lubrication characteristics of ferrofluid film for spiral groove mechanical seal in external electromagnetic field and…

Abstract

Purpose

The purpose of this study is to investigate the hydrodynamic lubrication characteristics of ferrofluid film for spiral groove mechanical seal in external electromagnetic field and to analyze the effects of the volume fraction of ferrofluid, parameters of the electromagnetic field, operating parameters and geometrical parameters of mechanical seal on the characteristics of ferrofluid film.

Design/methodology/approach

The relationship between the ferrofluid viscosity and the intensity of external electromagnetic field was established. Based on the Muijderman narrow groove theory, the pressure distribution was calculated with the trial method by trapezoid formula.

Findings

It was found that pressure, average viscosity, average density and opening force of ferrofluid between end faces increase with the increase in intensity of current, volume fraction of ferrofluid, rotating speed, pressure differential and spiral angle; decrease with the increase in temperature; and increase at first and then decrease with the increase in the ratio of groove width to weir and the groove length. All of them reach the maximum value when the ratio of width of groove to weir is 0.7 and the ratio of groove length is 0.6. Leakage of ferrofluid increases with an increase in intensity of current, volume fraction of ferrofluid, rotating speed, pressure differential, spiral angle and ratio of groove length; decreases with an increase in temperature; and increases at first and then decreases with the increase in the ratio of groove width to weir. The tendencies of characteristics of silicone oil are consistent with those of ferrofluid, and the characteristics of silicone oil are smaller than those of ferrofluid under the same condition.

Originality/value

The volume fraction of ferrofluid, rotating speed, spiral angle, ratio of groove width to weir, groove length and temperature have a significant influence on the characteristics of ferrofluid film; however, intensity of current and the pressure differential have slight influence on the characteristics of ferrofluid film. An analytical method for analyzing hydrodynamic lubrication characteristics of ferrofluid film in a spiral groove mechanical seal was proposed based on the Muijderman narrow groove theory.

Details

Industrial Lubrication and Tribology, vol. 70 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 10 August 2021

Bo Yu, Muming Hao, Sun Xinhui, Zengli Wang, Liu Fuyu and Li Yongfan

The purpose of this paper is to investigate the dynamic characteristics of spiral groove liquid film seal under the effect of thermal–fluid–solid coupling.

Abstract

Purpose

The purpose of this paper is to investigate the dynamic characteristics of spiral groove liquid film seal under the effect of thermal–fluid–solid coupling.

Design/methodology/approach

The dynamic analysis model of spiral groove liquid film seal under the effect of thermal–fluid–solid coupling was established by perturbation method. The steady-state and perturbation Reynolds equations were solved, and the steady-state sealing performance and dynamic characteristic coefficients of the liquid film were obtained.

Findings

Compared with the liquid film without coupling method, a divergent seal gap is formed between the seal rings under the effect of thermal–fluid–solid coupling, the minimum liquid film thickness decreases, the dynamic stiffness and damping coefficients of the liquid film are increased and the thermoelastic deformation of the end-face improves the dynamic performance of the liquid film seal.

Originality/value

The dynamic characteristics of the spiral groove liquid film seal under the effect of thermal–fluid–solid coupling are studied, which provides a theoretical reference for optimizing the dynamic performance of the non-contacting liquid film seal.

Details

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

Keywords

Article
Publication date: 30 November 2021

Yuan Chen, Hao Shang, Xiaolu Li, Yuntang Li, Bingqing Wang and Xudong Peng

The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove…

Abstract

Purpose

The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS).

Design/methodology/approach

The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed.

Findings

The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance.

Originality/value

The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

Details

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

Keywords

Article
Publication date: 12 May 2022

Cheng Zhang, Jianfeng Zhou and Xiannian Meng

In the magnetorheological fluid (MRF) sealing, a large amount of friction heat is generated in the fluid film with micron thickness due to the viscosity dissipation, which leads…

Abstract

Purpose

In the magnetorheological fluid (MRF) sealing, a large amount of friction heat is generated in the fluid film with micron thickness due to the viscosity dissipation, which leads to seal failure and MRF deterioration. The purpose of this study is to investigate the mechanism of temperature rise of MRF film under the action of the three-field coupling of the flow field, temperature field and magnetic field.

Design/methodology/approach

The fluid film was simplified as a Couette flow in this work to simulate the temperature change in the sealing fluid film under different working conditions. The corresponding experiment for test the temperature rise was also carried out, and the temperature of the characteristic point of the stationary ring was measured to validate the model.

Findings

The results show that the temperature rise is mainly affected by the rotational speed, magnetic field strength and fluid film thickness. The magnetic field enhances the convective heat transfer in the MRF film. The thinner the fluid film, the more frictional heat generated. The MRF film reaches its maximum temperature at the contact with the end face of rotating ring due to frictional heat.

Originality/value

A method for temperature rise analysis of MRF fluid sealing films based on Couette flow is established. It is helpful for the study of liquid film frictional heat in MRF seals.

Details

Industrial Lubrication and Tribology, vol. 74 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 7 August 2018

Songtao Hu, Noel Brunetiere, Weifeng Huang, Xi Shi, Zhike Peng, Xiangfeng Liu and Yuming Wang

Face contact has a strong impact on the service life of non-contacting gas face seals; the current research which mainly focuses on the face contact had appeared during the…

Abstract

Purpose

Face contact has a strong impact on the service life of non-contacting gas face seals; the current research which mainly focuses on the face contact had appeared during the startup or shutdown operation. This paper aims to present a closed-form contact model of a gas face seal during the opened operation.

Design/methodology/approach

Referring to the axial rub-impact model of rotor dynamics, a closed-form contact model is developed under a nonparallel plane contact condition that corresponds to the local face contact of sealing rings arising from some disturbances during the opened operation. The closed-form contact model and a direct numerical contact model are performed on Gaussian surfaces to compare the contact behavior.

Findings

The closed-form contact model is in a good agreement with the direct numerical contact model. However, the closed-form contact model cannot involve the influence of grooves on the sealing ends. The error is eliminated in some other types of gas face seals such as coned gas face seals. Besides non-contacting face seals, the closed-form model can be applied to the axial rub impact of rotor dynamics.

Originality value

A closed-form contact model of a gas face seal is established during the opened operation. The closed-form contact model is validated by a direct numerical contact model. The closed-form contact model also suits for axial rub-impact of rotor dynamics.

Details

Industrial Lubrication and Tribology, vol. 70 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 6 June 2022

Cong Zhang, Jinbo Jiang and Xudong Peng

This paper aims to acquire the phase distribution and sealing performance of supercritical carbon dioxide (SCO2) dry gas seals with phase transitions.

Abstract

Purpose

This paper aims to acquire the phase distribution and sealing performance of supercritical carbon dioxide (SCO2) dry gas seals with phase transitions.

Design/methodology/approach

The SCO2 spiral groove dry gas seal is taken as the research object. The finite differential method is applied to solve the governing equations. Furthermore, the phase distribution and the sealing performance are obtained. Compared to the ideal gas model, the effect of phase transitions on sealing performance is also explored.

Findings

Vaporization is likely to occur near the inner radius when SCO2 dry gas seals are operated near the critical point. Whether phase transitions are considered in the model affects the sealing performance seriously. When phase transitions are considered, the sealing performance depends significantly on the working conditions, and unexpected results are produced when inlet conditions approach the critical point.

Originality/value

The numerical model for SCO2 dry gas seals with phase transitions is established. The phase distribution and the sealing performance of SCO2 dry gas seals are explored.

Details

Industrial Lubrication and Tribology, vol. 74 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

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