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Article
Publication date: 3 July 2018

Dongju Chen, Jihong Han, Xianxian Cui and Jinwei Fan

To identify the dynamic feature of the aerostatic slider caused by gas film, an evaluation system by a piezoelectric acceleration sensor is presented in time and frequency domain.

Abstract

Purpose

To identify the dynamic feature of the aerostatic slider caused by gas film, an evaluation system by a piezoelectric acceleration sensor is presented in time and frequency domain.

Design/methodology/approach

The dynamic pressure fluctuation is evaluated by the wavelet transform, cross correlation analysis and power spectral density (PSD). Wavelet transform is used to process the measured result of the aerostatic slider and the signal is decomposed into high-frequency and low-frequency signal. Correlation analysis method is used to evaluate the impact of the initial gas gap on the fluctuation in time domain.

Findings

According to the PSD analysis of the processed signal in the frequency domain, the natural frequency of the aerostatic slider is identified from the measured signal in frequency domain; this method provides a basis for the identification of guideway errors.

Research limitations/implications

The method can also be applied to the error identification of other components of the machine tool.

Originality/value

Wavelet transform is used to process the measured result of the aerostatic slider by acceleration sensor, and the signal is decomposed into high-frequency and low-frequency signal. Correlation analysis method is used to evaluate the impact of the initial gas gap on the fluctuation in time domain. According to the PSD analysis of the processed signal in the frequency domain, the natural frequency of the aerostatic slider is identified from the measured signal in frequency domain; this method provides a basis for the identification of slider errors.

Details

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

Keywords

Article
Publication date: 10 July 2017

Dongju Chen, Jihong Han, Chen Huo, Jinwei Fan and Qiang Cheng

This paper aims to better understand the dynamic characteristics of an aerostatic slider caused by a gas film, and the impact of a gas film slip on the load capacity, stiffness…

Abstract

Purpose

This paper aims to better understand the dynamic characteristics of an aerostatic slider caused by a gas film, and the impact of a gas film slip on the load capacity, stiffness and dynamic stiffness of the guideway is studied.

Design/methodology/approach

In theory, the Navier velocity slip model is introduced for fluid continuous flow equation to calculate the flow state in the micro-state; in experimental techniques, the stiffness experiment of the guideway by digital inductance meter is performed under different loadings, which are used to inspect the simulation results.

Findings

The maximum value of bearing stiffness in the condition of considering that the gas slip is larger than that of not considering the gas slip, and the gas film clearance of maximum bearing stiffness in the condition of considering the gas slip is less than that of not considering the gas slip. This is verified by the measurement of the stiffness of the guideway.

Originality/value

This paper mostly studies the influence of the gas slip effects on the performance of the aerostatic guideway, which will make a certain contribution to the guideway stability and the machining precision of the machine tool.

Details

Industrial Lubrication and Tribology, vol. 69 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 25 August 2020

Dongju Chen, Shuai Kong, Jingfang Liu and Jinwei Fan

The purpose of this paper is to propose the pressure fluctuation to further evaluate and predict the dynamic and static characteristics of the aerostatic slider and improve the…

Abstract

Purpose

The purpose of this paper is to propose the pressure fluctuation to further evaluate and predict the dynamic and static characteristics of the aerostatic slider and improve the calculation accuracy of the aerostatic slider.

Design/methodology/approach

First-order velocity slip is introduced into the traditional gas-film fluid equation, and the numerical analysis method is used to solve the static performance of the aerostatic slider. The finite element analysis method is used to solve its dynamic characteristics.

Findings

It can be concluded from the simulation and experimental results that the model considering the velocity slip in the gas film flow is more accurate. The errors between the modal detection results and the vibration detection results (0.8%–5.8%) under speed slip are smaller than the traditional cases (23.7%–210%), which also verifies the correctness of the above conclusions.

Originality/value

In this paper, the method of simulation and experiment is used to prove that the first-order velocity slip model is more suitable to predict the dynamic response of the aerostatic slider than the condition without slip.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0059/

Details

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

Keywords

Article
Publication date: 20 March 2024

Heji Zhang, Dezhao Lu, Wei Pan, Xing Rong and Yongtao Zhang

The purpose of this study is to design a closed hydrostatic guideway has the ability to resist large-side load, pitch moments and yaw moments, has good stiffness and damping…

Abstract

Purpose

The purpose of this study is to design a closed hydrostatic guideway has the ability to resist large-side load, pitch moments and yaw moments, has good stiffness and damping characteristics, and provides certain beneficial guidance for the design of large-span closed hydrostatic guideway on the basis of providing a large vertical load bearing capacity.

Design/methodology/approach

The Reynolds’ equation and flow continuity equation are solved simultaneously by the finite difference method, and the perturbation method and the finite disturbance method is used for calculating the dynamic characteristics. The static and dynamic characteristics, including recess pressure, flow of lubricating oil, carrying capacity, pitch moment, yaw moment, dynamic stiffness and damping, are comprehensively analyzed.

Findings

The designed closed hydrostatic guideway has the ability to resist large lateral load, pitch moment and yaw moment and has good stiffness and damping characteristics, on the basis of being able to provide large vertical carrying capacity, which can meet the application requirements of heavy two-plate injection molding machine (TPIMM).

Originality/value

This paper researches static and dynamic characteristics of a large-span six-slider closed hydrostatic guideway used in heavy TPIMM, emphatically considering pitch moment and yaw moment. Some useful guidance is given for the design of large-span closed hydrostatic guideway.

Details

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

Keywords

Article
Publication date: 9 December 2019

Ruzhong Yan, Liaoyuan Wang and Shengze Wang

The purpose of this paper is to study the mechanical properties of aerostatic guideway taking the structural deformation into account, and further improve the calculation method…

Abstract

Purpose

The purpose of this paper is to study the mechanical properties of aerostatic guideway taking the structural deformation into account, and further improve the calculation method of guideway.

Design/methodology/approach

A theoretical model of fluid-structure interaction for the numerical simulation was established and mechanical properties of the aerostatic guideway with porous restrictors were solved based on computational fluid dynamics. The deformation law of the guideway with different materials and gas-film thicknesses was revealed, and its static and dynamic characteristic curves were obtained.

Findings

The results indicate that ceramics as the material of guideways exhibit good applicability due to the small deformation, the quick dynamic response and the relatively light weight. The rational initial gas-film of guideway is recommended.

Originality/value

The present work can provide ideas for the design and optimization of aerostatic guideways.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0288

Details

Industrial Lubrication and Tribology, vol. 72 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 30 June 2022

Arun Bangotra and Sanjay Sharma

This study aims to investigate the impact of surface waviness on the static performance parameters of hydrodynamic journal bearings operating with lubricants containing copper…

Abstract

Purpose

This study aims to investigate the impact of surface waviness on the static performance parameters of hydrodynamic journal bearings operating with lubricants containing copper oxide (CuO) and cerium oxide (CeO2) nanoparticles.

Design/methodology/approach

The static performance parameters of bearings with surface waviness and the addition of nanoparticles in lubricants were calculated using the nondimensional form of Reynolds equation and finite element method. Static performance parameters are calculated at different waviness numbers in the circumferential, axial and both directions at various wave amplitudes with variable viscosities of lubricants with nanoparticles using the viscosity equation forming a relationship between the relative viscosity, temperature and weight fraction of nanoparticles in lubricant developed from the experimental results.

Findings

The computed results indicate that the impact of waviness on the bearing surface enhances the load capacity, reduces friction coefficient, and is more effective in the circumferential direction than in the axial direction or in both directions. The addition of CuO and CeO2 to the lubricant enhanced its viscosity which further improved the steady-state parameters of the wave bearing.

Research limitations/implications

This study is based on a numerical technique, which has significant limitations, and the simulated results must be tested experimentally.

Practical implications

The current findings will be beneficial for designers to improve the performance of hydrodynamic journal bearings.

Originality/value

The calculated results demonstrate that the combined effect of the surface waviness on bearings and the addition of nanoparticles to lubricants can greatly increase the performance of hydrodynamic journal bearings.

Details

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

Keywords

Content available
Article
Publication date: 1 February 1998

388

Abstract

Details

Industrial Lubrication and Tribology, vol. 50 no. 1
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 25 June 2019

Vivek Kumar and Satish C. Sharma

This paper aims to numerically investigate the influence of magnetic field and recess configurations on performance of hydrostatic thrust bearing. Electrically conducting fluid is…

Abstract

Purpose

This paper aims to numerically investigate the influence of magnetic field and recess configurations on performance of hydrostatic thrust bearing. Electrically conducting fluid is supplied to bearing, operating in external magnetic field. Influences of recess geometric shapes (circular, rectangular, elliptical and triangular) and restrictor (capillary and orifice) are numerically examined on stead-state and dynamic performance characteristics of bearing.

Design/methodology/approach

Numerical simulation of hydrostatic thrust bearing has been performed using finite element (FE) method based on Galerkin’s technique. An iterative source code based on FE approach, Gauss–Siedel and Newton–Raphson method is used to compute steady-state and dynamic performance indices of bearings.

Findings

The presence of magnetic field is observed to be enhancing load-carrying capacity and damping coefficient of bearings. The effect is observed to be more pronounced at low value of Hartmann number, because of the saturation effect observed at higher values of Hartmann number. The enhancement in abovementioned performance indices is observed to be highly dependent on geometry of recess and restrictor.

Research limitations/implications

This study presents a FE-based approach to numerically simulate a hydrostatic thrust bearing. It will help bearing designers and academician in selecting an appropriate recess shape, restrictor and strength of magnetic field, for obtaining optimum performance from hydrostatic thrust bearing.

Originality/value

The present investigation provides a coupled solution of modified Reynolds equation and restrictor equation, which is essential for accurately predicting the performance of hydrostatic thrust bearings.

Details

Industrial Lubrication and Tribology, vol. 71 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 2 August 2022

Cheng Xiong, Bo Xu, Yulong Jiang, Xiangyu Lu and Zhenqian Chen

This study aims to investigate the thermohydrodynamic (THD) and thermoelastohydrodynamic (TEHD) performance of an air-lubricated thrust bearing under different slip conditions…

Abstract

Purpose

This study aims to investigate the thermohydrodynamic (THD) and thermoelastohydrodynamic (TEHD) performance of an air-lubricated thrust bearing under different slip conditions, especially the slip length effect.

Design/methodology/approach

In this study, a new modified boundary slip model was established to investigate thrust bearing performance. The THD and TEHD bearing characteristic distribution was analyzed with fluid–thermal–structure interaction approach. The effect of the slip length on the bearing performance was studied using various bearing structure parameters.

Findings

The increased slip length changed the classical feature distribution of the film pressure and temperature. The sacrifice of the bearing load capacity effectively compensated for the aerodynamic thermal effect and friction torque under the slip condition. The TEHD model has a lower film pressure and load capacity than the THD model. However, it also has lower film temperature, lower friction torque and smaller Knudsen number (Kn).

Originality/value

The bearing THD and TEHD performances of the modified boundary slip model were compared with those of a traditional no-slip bearing. The results help to guide the selection of the bearing surface materials and processing technology of rotor and foil, so as to fully control the degree of slip and make use of it.

Details

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

Keywords

Article
Publication date: 8 February 2016

Zhaoxu Jin, Shuangxi Li, Jining Cai and qiuxiang zhang

This paper aims to introduce a new type of analysis method to seek the actual working performance of the regulatable dry gas seal, including equilibrium film thickness…

Abstract

Purpose

This paper aims to introduce a new type of analysis method to seek the actual working performance of the regulatable dry gas seal, including equilibrium film thickness, stiffness-leakage ratio and so on. Additionally, a parametric optimization of the hydrostatic structure is completed for this kind of seal.

Design/methodology/approach

From the point of axial force balance based on gas lubrication theory, a new analysis method, the Gas Film Divided Method, has been introduced. A four-factor and three-level hydrostatic structural parameters test scheme is designed by means of Central Composite Design test and then the hydrostatic structural parameters of regulatable dry gas seal were optimized. Three types of regulatable dry gas seal have been designed and manufactured to verify the theoretical analysis by measuring the equilibrium film thickness and inward leakage.

Findings

The results indicate that the numerical values of the Gas Film Divided (GFD) method agree well with the experimental ones. Test proves that the Central Composite Design test could achieve optimized hydrostatic structural parameters of regulatable dry gas seal effectively.

Research limitations/implications

For validating the correctness of the GFD method, an experiment study of the regulatable dry gas seal is being carried out where atmosphere is selected as the lubricant for the sake of safety. Soon after, the author will discuss the application in the new paper.

Originality/value

The introduction of the GFD method proffers important insights to seek the performances of regulatable dry gas seal under the actual working conditions. The detailed optimal values of the hydrostatic structural parameters were given by the theoretical research which may be helpful for the design of regulatable dry gas seal.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 15