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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

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Article
Publication date: 8 April 2014

Jun Sun, Xinlong Zhu, Liang Zhang, Xianyi Wang, Chunmei Wang, Hu Wang and Xiaoyong Zhao

Current lubrication analyses of misaligned journal bearings were generally performed under some given preconditions. To make the lubrication analysis closer to the actual…

Abstract

Purpose

Current lubrication analyses of misaligned journal bearings were generally performed under some given preconditions. To make the lubrication analysis closer to the actual situation and usable to the journal bearing design, the purpose of this paper was to calculate the lubrication characteristics of misaligned journal bearings considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time.

Design/methodology/approach

The lubrication of bearings was analyzed using the average Reynolds equation. The deformation of the bearing surface under oil film pressure was calculated by a compliance matrix method. The compliance matrix was established by finite element analysis of the bearing housing. The viscosity-pressure and viscosity–temperature equations were used in the analysis.

Findings

The oil viscosity-pressure relationship has a significant effect on the lubrication of misaligned journal bearings. The surface roughness will affect the lubrication of misaligned journal bearings when the eccentricity ratio and angle of journal misalignment are all large. The directional parameter of the surface has an obvious effect on the lubrication of misaligned journal bearings. The deformation of the bearing surface has a remarkable effect on the lubrication of misaligned journal bearings.

Originality/value

The lubrication characteristics of misaligned journal bearings were calculated considering the viscosity-pressure effect of the oil, the surface roughness and the elastic deformation of the journal bearing at the same time. The results of this paper are helpful to the design of the bearing.

Details

Industrial Lubrication and Tribology, vol. 66 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 May 2018

Aibin Zhu, Hongling Wu, Yulei Yang and Shengli He

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model…

Abstract

Purpose

Because of the various geometric descriptions of different bearing types, performance calculation of journal bearing is complicated, and is difficult in traditional model. This paper aims to simplify the calculation of the journal bearing performance, and to reduce the workload.

Design/methodology/approach

On the basis of previous research, a general performance calculation model of journal bearing is proposed in this paper. Eccentricity ratio and attitude angle of axis to each pad are calculated by coordinates of spindle center and each pad center by establishing the unified coordinate system. The surface deformation of journal bearing is taken into consideration, and a correction value is added to the dimensionless oil film thickness.

Findings

The performance calculation results of various fix-pad and tilting-pad journal bearings match the results of the existing references very well, revealing the validity of the model. The general model can greatly reduce programming workload, and increase adaptability to different bearings.

Originality/value

Geometric descriptions of both fix-pad and tilting-pad journal bearings are unified in this model, which can be applied to both standard and non-standard journal bearings with different preload ratios. In addition, due to the unification of different bearings types, this model is more conducive to performance comparison among different bearing types, and promotes the development of new structural forms for journal bearings.

Details

Industrial Lubrication and Tribology, vol. 70 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 19 June 2009

J. Sharana Basavaraja, Sathish Sharma and Sathish Jain

The non‐recessed hybrid journal bearings of cylindrical type, when operating at higher rotational speeds can suffer self‐exited vibrations(oil‐whirl Instability), which…

Abstract

Purpose

The non‐recessed hybrid journal bearings of cylindrical type, when operating at higher rotational speeds can suffer self‐exited vibrations(oil‐whirl Instability), which can cause excessive rotor motion causing bearing and sometimes total machine failure. The multi‐lobe journal bearing exhibits better stability as well as a superior capability to suppress oil‐whirl. The paper aims to present a theoretical study pertaining to a two‐lobe hole‐entry hybrid journal bearing by considering the combined influence of surface roughness and journal misalignment on the performance of the bearing.

Design/methodology/approach

The average Reynolds equation governing the flow of lubricant in the clearance space between the rough bearing surfaces together with the equation of flow through a capillary restrictor has been solved using FEM. The bearing performance characteristics have been simulated for a two‐lobe hole‐entry hybrid journal bearing for the various values of offset factor, restrictor design parameter, surface roughness parameter, surface pattern parameter and journal misalignment parameters.

Findings

The two‐lobe hole‐entry hybrid journal bearing system with an offset factor greater than one indicates significant improvement of the order of 15‐25 percent in the values of direct stiffness and direct damping coefficients compared to a circular hole‐entry hybrid journal bearing system. Also the lubricant flow of a two‐lobe hole‐entry hybrid journal bearing is reduced by 25 percent vis‐à‐vis circular bearing.

Originality/value

The present work is original of its kind, in case of two‐lobe hole‐entry hybrid journal bearing. The results are quite useful for the bearing designer.

Details

Industrial Lubrication and Tribology, vol. 61 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 November 2006

Ludovico Morais and Luís Andrade Ferreira

To provide an optimization methodology for the journal bearings of mass balancing systems, that consists in a sensibility analysis of the journal bearings design…

Abstract

Purpose

To provide an optimization methodology for the journal bearings of mass balancing systems, that consists in a sensibility analysis of the journal bearings design parameters in the journal bearing operating parameters, as well as the comparison and selection of the journal bearing materials and the selection of the lubrication grooves suitable.

Design/methodology/approach

The methodology followed comprehends three steps. The first step is the one by one variation of the journal bearing design parameters (radial clearance, journal bearing diameter and journal bearing length) to analyse, independently, their influence on the journal bearing operating parameters (minimum film thickness, maximum pressure and power loss). The second step is the analysis and comparison of the metallic materials that can be used in the journal bearings. The third step is the selection of the lubrication groove.

Findings

Applying this methodology it is shown that increasing the radial clearance the minimum film thickness increases and the maximum pressure and the power loss decrease, increasing the journal bearing length the minimum film thickness and the power loss increase and the maximum pressure decreases, at last, increasing the journal bearing diameter the minimum film thickness, the maximum pressure and the power loss increase. The materials that should be used are the white metals (Babbitts). And the journal bearing lubrication grooves should be circumferential.

Practical implications

This method gives the user the possibility to eliminate potential failures of the journal bearings, or simply to make a sensibility study of the influence of the journal bearing design parameters in the operating ones.

Originality/value

This paper provides a simple and objective methodology to make a sensibility analysis of the influence of the journal bearing design parameters in the operating parameters, as well as select the journal bearing materials and lubrication grooves.

Details

Industrial Lubrication and Tribology, vol. 58 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 28 September 2010

Satish Jain, Satish Sharma, J. Sharana Basavaraja and Prashant Kushare

In recent years, researchers have focused a great deal of attention on multirecess hybrid journal bearing systems. The non‐circular journal bearings are widely used in…

Abstract

Purpose

In recent years, researchers have focused a great deal of attention on multirecess hybrid journal bearing systems. The non‐circular journal bearings are widely used in industry on account of their better stability, simplicity, efficiency and low cost. The purpose of this paper is to present a theoretical investigation into the performance of a two‐lobe multirecess hybrid journal bearing system.

Design/methodology/approach

The Reynold's equation governing the lubricant flow in the clearance space between the journal and bearing together with restrictor flow equations has been solved using finite element method. The bearing static and dynamic performance characteristics have been presented for the various values of the offset factors (0.75, 1, 1.25 and 1.50) for the hybrid mode of operation of the journal bearing system compensated by capillary and orifice restrictors for the commonly used bearing operating and geometric parameters. The offset of the journal has been accounted for by defining a non‐dimensional factor called offset factor delta.

Findings

The numerically simulated results indicate that a two‐lobe four recessed hybrid journal bearing provides a better performance than the corresponding similar circular recessed journal bearing system. The study further reveals that in order to get an improved performance of a two‐lobe four recessed journal bearing, a proper selection of bearing offset factors along with type of restrictor (capillary or orifice) is essential.

Originality/value

The results presented in this paper are useful for bearing designers.

Details

Industrial Lubrication and Tribology, vol. 62 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 17 August 2010

Satish Sharma, Satish Jain, J. Sharana Basavaraja and Neeraj Sharma

Hole‐entry hybrid journal bearings are widely used in many applications owing to their favourable characteristics. Ever increasing technological developments demand much…

Abstract

Purpose

Hole‐entry hybrid journal bearings are widely used in many applications owing to their favourable characteristics. Ever increasing technological developments demand much improved performance from these class of bearings operating under the most stringent, exact and precise conditions. Therefore, it becomes imperative that the hole‐entry journal bearings be designed on the basis of more accurately predicted bearing characteristics data. The purpose of this paper is to describe a theoretical study to demonstrate the combined influence of the effect of pocket size at the outlet of supply holes and the journal misalignment on the performance of an orifice compensated hole‐entry hybrid journal bearing system.

Design/methodology/approach

Finite element method is used to solve the Reynolds equation governing the flow of an incompressible lubricant in the clearance space between the journal and bearing together with equation of flow through an orifice. The journal misalignment has been accounted for by defining a pair of misalignment parameters sigma and delta. The effect of pocket size at the outlet of supply holes has been accounted by defining a non‐dimensional parameter which is function of diameter of pocket and journal diameter.

Findings

The results presented in this paper indicate that the effect of journal misalignment is, in general, to cause a reduction in bearing dynamic characteristics parameters whereas the effect of pocket size is to slightly compensate this loss. Performance of a two lobe four recessed journal bearing, a proper selection of bearing offset factor along with type of restrictor (capillary or orifice) is essential.

Originality/value

This paper presents valuable data relating to hole‐entry hybrid journal bearings useful for bearing designers.

Details

Industrial Lubrication and Tribology, vol. 62 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 4 February 2014

Hem Chander Garg and Vijay Kumar

The slot-entry hybrid journal bearings have been successfully used in various engineering applications because of their good performance over wide range of speed and load…

Abstract

Purpose

The slot-entry hybrid journal bearings have been successfully used in various engineering applications because of their good performance over wide range of speed and load, besides their relative simplicity in manufacturing. Most of the research work pertaining to non-recessed journal bearing assumes standard symmetric and asymmetric configurations. However, many more configurations are possible by changing the position of slot which may improve the performance of the slot-entry journal bearing. In the present work study of static performance characteristics of slot-entry journal bearing of different configuration has been carried out. The paper aims to discuss these issues.

Design/methodology/approach

FEM has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The performance characteristics of slot-entry hybrid journal bearings are computed by developing a computer program.

Findings

The simulated results of bearing characteristics parameters in terms of minimum fluid-film thickness and bearing flow have been presented for the wide range of various values of non-linearity factor and external load. It is found that there is an increase in the oil requirement for slot-entry hybrid journal bearing with the specified operating and geometric parameters, when the viscosity of the lubricant decreases due to the non-Newtonian behavior of the lubricant. The effect of the decrease in the viscosity of the lubricant due to non-Newtonian behavior of the lubricant diminishes the attitude angle. The computed performance characteristics are helpful for the bearing designer while choosing a particular configuration of bearing.

Research limitations/implications

The performance characteristics have been computed by considering the non-Newtonian lubricants. The thermal effects have been ignored in the analysis so as to obviate the mathematical complexity.

Originality/value

Get idea from already published manuscripts.

Details

Industrial Lubrication and Tribology, vol. 66 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 August 2019

Guo Xiang Guo Xiang, Yanfeng Han, Renxiang Chen, Jiaxu Wang Jiaxu Wang and Ni Xiaokang

This paper aims to present a numerical model to investigate the mixed lubrication performances of journal-thrust coupled bearings (or coupled bearings).

Abstract

Purpose

This paper aims to present a numerical model to investigate the mixed lubrication performances of journal-thrust coupled bearings (or coupled bearings).

Design/methodology/approach

The coupled hydrodynamic effect (or coupled effect) between the journal and the thrust bearing is considered by ensuring the continuity of the hydrodynamic pressure and the flow field at the common boundary. The mixed lubrication performances of the coupled bearing are comparatively studied for the cases of considering and not considering coupled effect.

Findings

The simulated results show that the hydrodynamic pressure distributions for both the journal and thrust bearing are modified due to the coupled effect. The decreased load capacity of the journal bearing and the increased load capacity of the thrust bearing can be observed when the coupled effect is considered. And the coupled effect can facilitate in reducing the asperity contact load for both the journal and thrust bearing. Additionally, the interaction between the mixed lubrication behaviors, especially for the friction coefficient, of the journal and the thrust bearing is significant in the elastohydrodynamic lubrication regime, while it becomes weak in the mixed lubrication regime.

Originality/value

The developed model can reveal the mutual effects of the mixed lubrication behavior between the journal and the thrust bearing.

Details

Industrial Lubrication and Tribology, vol. 71 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 4 September 2017

Nimeshchandra S. Patel, Dipak Vakharia and Gunamani Deheri

This paper aims to investigate the performance of a ferrofluid-based hydrodynamic journal bearing system.

Abstract

Purpose

This paper aims to investigate the performance of a ferrofluid-based hydrodynamic journal bearing system.

Design/methodology/approach

This paper presents a new design of ferrofluid-based hydrodynamic journal bearing. An experimental set-up consisting of a magnetic shaft along with a brass bearing was modified and developed. A permanent magnet was used to make the selected shaft material magnetic. The load and speed were varied to conduct the analyses for different test conditions.

Findings

The paper provides information about a design of ferrofluid-based journal bearing and its improved performances. For moderate to higher loads at different shaft speeds, it was found that because of the magnetization effect, the maximum film pressure in case of a ferrofluid lubricant increased up to approximately 60 per cent, compared with that of the conventional lubricant-based journal bearing system. Besides, the temperature rise was found smaller for ferrofluid lubricants, thus making the system cooler while running.

Originality/value

This paper offers a new design of magnetic bearing system for the experimental analysis by utilizing a magnetic shaft with a non-magnetic bearing. The present ferrofluid-based bearing design is less complicated from manufacturing point of view.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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