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Article
Publication date: 30 August 2023

Jian Wei, XiaoYue Sun, Jing Tian and CaiHong Liu

This paper aims to study the impact of transient velocity changes on sealing performance during reciprocating sealing processes.

97

Abstract

Purpose

This paper aims to study the impact of transient velocity changes on sealing performance during reciprocating sealing processes.

Design/methodology/approach

Establish a model of transient mixed lubrication, solve the transient Reynolds equation, consider the effect of temperature rise at the seal interfaces, and determine the behavior of the seal interfaces, such as film thickness and fluid pressure. Evaluation with friction and leakage rate, calculate the variation of sealing performance with reciprocating velocity under different working conditions, and verify it through bench experiments.

Findings

Within a reciprocating stroke, the frictional force decreases with increasing velocity, and the frictional force of the outstroke is greater than that of the instroke; at the time of the stroke transition, the fluid pressure is smallest and the rough peak contact pressure is greatest. At present, the dynamic pressure effect of fluids is the largest, and the friction force also increases, which increases the risk of material wear and failure. Friction and leakage increase with increasing pressure and root mean square roughness. As temperature increases, friction increases and leakage decreases. In studying the performance variations of seal components through a reciprocating sealing experiment, it was found that the friction force decreases with increasing velocity, which is consistent with the calculated results and more similar to the calculated results considering the temperature rise.

Originality/value

This study provides a reference for the study of transient sealing performance.

Details

Industrial Lubrication and Tribology, vol. 75 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 19 May 2021

Hua-Lin Yang, Xiulong Li, Weiwei Sun, Fang Deng and Jie Du

This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal.

Abstract

Purpose

This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal.

Design/methodology/approach

The model consists of a finite element analysis of the contact pressure, a fluid mechanics analysis of the fluid film, a contact analysis of the asperity contact pressure, a deformation analysis of the seal lip and an iterative numerical simulation process.

Findings

Simulation results show that the leakage is in direct proportion to the seal roughness and speed, and in inverse proportion to the fluid viscosity. Comparisons with the experimental results verify the validity of the mixed EHL model.

Originality/value

This study provides a helpful method to calculate the leakage of the skeleton reciprocating oil seal, which shortens its development cycles.

Details

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

Keywords

Article
Publication date: 9 February 2010

Jian Yang

The purpose of this paper is to investigate, theoretically and experimentally, the sealing performance of the axial piston seal on a larger diameter (100 mm in diameter) axial…

411

Abstract

Purpose

The purpose of this paper is to investigate, theoretically and experimentally, the sealing performance of the axial piston seal on a larger diameter (100 mm in diameter) axial piston and reveal the sealing mechanism of the axial piston.

Design/methodology/approach

Based on the characteristics of the clearance flow between the seal and the piston, reasonable boundary conditions for Navier‐Stokes' equations are determined and the equations are modified, so that the final equations can describe the real flow state of the clearance flow.

Findings

Through combining the final equations with finite element method, the pressure distributions within the clearance field for the sealing part during the reciprocating motion of the piston and the leakage rate with the pressure are obtained. The deflections of the sealing part which affect sealing performance have been given.

Originality/value

Theoretical and experimental results show the internal relationship between the seal and the piston, also help to develop some newer piston pumps and improve on the seals of present high‐pressure piston pumps.

Details

Industrial Lubrication and Tribology, vol. 62 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 March 1950

T.E. BEACHAM and F.H. TOWLER

In recent years, considerable advances have been made in the prevention of leakage of liquids and oils past moving surfaces. Leakage is the most common source of complaint with…

Abstract

In recent years, considerable advances have been made in the prevention of leakage of liquids and oils past moving surfaces. Leakage is the most common source of complaint with regard to hydraulic machinery, in which field the authors have had considerable experience. The subject covers a wide field and, has been limited by excluding hydraulic joints. For the purpose of these papers, a hydraulic seal is defined as one whose function it is to prevent the leakage of liquid between surfaces having relative movement.

Details

Industrial Lubrication and Tribology, vol. 2 no. 3
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 June 1975

B.S. NAU

FLUID SEALING research at BHRA Fluid Engineering has its roots in the early years following the 1939–45 war. In 1945 the then Ministry of Aircraft Production felt that the…

Abstract

FLUID SEALING research at BHRA Fluid Engineering has its roots in the early years following the 1939–45 war. In 1945 the then Ministry of Aircraft Production felt that the equipment designer needed sound, basic information on the way hydraulic jack seals functioned and the factors affecting their performance. D. F. Denny was therefore seconded to Imperial College, London, to undertaken programme of research on reciprocating oil seals, which resulted in the publication of a 120‐page volume: “The sealing mechanism of flexible packings”, recently reprinted to meet a continuing demand.

Details

Industrial Lubrication and Tribology, vol. 27 no. 6
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 8 August 2018

Han Qing, LiangXi Xie, Lu Li and Chuang Jia

This paper aims to establish a numerical model to calculate contact pressure for rectangular vane sealing surface of hydraulic rotary actuator. Numerical model can be applied to…

126

Abstract

Purpose

This paper aims to establish a numerical model to calculate contact pressure for rectangular vane sealing surface of hydraulic rotary actuator. Numerical model can be applied to solve the steady-state Reynolds equation after the oil film thickness and the contact pressure distribution curve of the vane sealing surface are obtained.

Design/methodology/approach

The authors established the numerical model of contact pressure base on the theory of elastic after, the Reynolds equation is solved by the inverse solution.

Findings

The relationship between the oil film thickness of vane sealing surface and the contact pressure on different sealing location for hydraulic rotary actuator is obtained. At the same time, the lubrication state on the surface of seal is also found when the hydraulic rotary actuator runs stably.

Originality/value

The study shows that the lubricating state of the vane sealing surface is mixed lubrication, when the rotor of the hydraulic rotary actuator is running stably at a certain speed. Meanwhile, this research will provide a theory basis for later experiment for the hydraulic rotary vane actuator.

Details

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

Keywords

Article
Publication date: 26 October 2018

Shixian Xu, Zhengtao Su and Jian Wu

This paper aims to research the influence of pressure, friction factors, roughness and actuating speed to the mixed lubrication models of outstroke and instroke.

Abstract

Purpose

This paper aims to research the influence of pressure, friction factors, roughness and actuating speed to the mixed lubrication models of outstroke and instroke.

Design/methodology/approach

Mixed lubrication model is solved by finite volume method, which consists of coupled fluid mechanics, deformation mechanics and contact mechanics analyses. The influence of friction factor on the finite element model is also considered. Then, contact pressure, film thickness, friction and leakage have been studied.

Findings

It was found that the amount of leakage is sensitive to the film thickness. The larger the film thickness is, the greater the influence received from the friction factor, however, the effect of oil film on the friction is negligible. The friction is determined mainly by the contact pressure. The trend of friction and leakage influenced by actuating velocity and roughness is also obtained.

Originality/value

The influence of friction factor on the finite element model is considered. This can make the calculation more accurate.

Details

Industrial Lubrication and Tribology, vol. 71 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 August 2009

Xue‐Bin Yang, Xin‐Qiao Jin, Zhi‐Min Du, Tian‐Sheng Cui and Shao‐Kan Yang

The purpose of this paper is to investigate the frictional behavior of polytetrafluoroethylene (PTFE) composites under oil‐free sliding conditions.

Abstract

Purpose

The purpose of this paper is to investigate the frictional behavior of polytetrafluoroethylene (PTFE) composites under oil‐free sliding conditions.

Design/methodology/approach

The friction force and power consumption of pressure packing seals, which were, respectively, made of common filled PTFE, 30 wt% CF (carbon fiber) + PTFE and C/C (carbon/carbon) + PTFE, are studied in a reciprocating oil‐free compressor arrangement. Their coefficient of friction is tested on a block‐on‐ring type tribometer.

Findings

The results indicate that influence of mean sliding velocity on filled PTFE composites is apparently more predominant than the others. The friction force curvilinear path of 30 wt% CF+PTFE is hardly influenced by changing crankshaft turn angle. For C/C+PTFE, the effect of mean piston velocity on friction force is not evident. The results also indicate that the friction coefficient of C/C+PTFE is lower than that of 30 wt% CF+PTFE if their applied normal force exceeds 9.8 N. Furthermore, their variation curve of friction force is little different and the power consumption of C/C+PTFE is slightly higher than that of 30 wt% CF+PTFE.

Research limitations/implications

Neither the effect of real contact area on friction coefficient measured in a tribometer nor the influence of the temperature on friction force and power tested in a compressor is not taken into consideration here.

Practical implications

Owing to its good mechanical performances and frictional behaviors, C/C+PTFE is an optimum and promising material under conditions with sealing pressure up to 10 MPa and sliding velocity exceeding 4.0 m/s.

Originality/value

A novel material called C/C+PTFE is considered to make packing rings for oil‐free reciprocating compressors and its friction behaviour is tested on a refitted compressor.

Details

Industrial Lubrication and Tribology, vol. 61 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 25 January 2024

Chun Qiang Jia, Aofei Wang, Ling Yu and Li Zong

The rock drill’s drill tail experiences high-frequency fretting simultaneously in the rotational and axial directions. Due to the complex working characteristics and the low…

Abstract

Purpose

The rock drill’s drill tail experiences high-frequency fretting simultaneously in the rotational and axial directions. Due to the complex working characteristics and the low viscosity of the water medium, the pure water seal is susceptible to damage and failure. The purpose of this paper is to enhance the water seal’s performance.

Design/methodology/approach

The Y-shaped seal ring is modeled and simulated using orthogonal testing. Through analysis of the impact of various seal section parameters on sealing performance, the maximum contact stress and maximum Von Mises stress are selected as indicators of sealing effectiveness.

Findings

The maximum contact stress is proportional to lip thickness and chamfer length but inversely proportional to lip length. Meanwhile, the maximum Von Mises stress is directly influenced by lip depth and the included angle of the lip and drill tail but is inversely proportional to the lip thickness. The enhanced Y-shaped water seal sees reductions of 15% and 45% in maximum contact stress and maximum Von Mises stress, respectively.

Originality/value

This paper used analytical method and model that is helpful for design of the water seal’s structure in complex working characteristics and the low viscosity of the water medium.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2023-0366/

Details

Industrial Lubrication and Tribology, vol. 76 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 March 1993

Expertise in fluid engineering remains the core activity of the BHR Group. Over 46 years it has grown and diversified to meet the needs of its members for software, conferences…

Abstract

Expertise in fluid engineering remains the core activity of the BHR Group. Over 46 years it has grown and diversified to meet the needs of its members for software, conferences, publications, research and development programmes, and hardware production.

Details

Industrial Lubrication and Tribology, vol. 45 no. 3
Type: Research Article
ISSN: 0036-8792

1 – 10 of 652