Modeling a Hydrodynamic Bearing With Provision for Misalignments and Textures

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Chunxing Gu ◽  
Xianghui Meng ◽  
Shuwen Wang ◽  
Xiaohong Ding
Keyword(s):  
High Efficiency ◽  
Journal Bearing ◽  
Effective Means ◽  
Surface Texturing ◽  
Tribological Performance ◽  
Journal Bearings ◽  
Time Varying ◽  
Hydrodynamic Bearing ◽  
Proposed Model ◽  
Effect Of Surface

Abstract Surface texturing is one effective means to improve bearing performance. Available studies are mainly focused on the perfectly aligned journal bearing with textures. The studies involving the effect of surface texturing on the misaligned bearing are still limited. In the present study, a transient mixed lubrication model that allows predicting evolution of friction characteristics with high efficiency was proposed. The misalignment of journal bearing under the time-varying applied load was considered using two deflection angles. The performance of journal bearing with provision for misalignments and textures was studied using the proposed model. The results involving the orbits of the journal center and the energy loss of different misaligned journal bearings were obtained. The influences of misalignment degree and surface texturing on these parameters were analyzed. The results show that along with the increased deflection angles, the effect of texturing on the tribological performance of journal bearing would turn beneficial into harmful.

scholarly journals The effect of textured surfaces on the hydrodynamic pressure generation in journal bearings

2018 ◽  
Vol 204 ◽  
pp. 04006
Author(s):  
Muchammad ◽  
Mohammad Tauviqirrahman ◽  
Rizqy Amanullah Akbar ◽  
Fuad Hilmy ◽  
Jamari
Keyword(s):  
Journal Bearing ◽  
Fluid Dynamic ◽  
Surface Texturing ◽  
Hydrodynamic Pressure ◽  
Journal Bearings ◽  
Hydrodynamic Performance ◽  
Textured Surfaces ◽  
Eccentricity Ratio ◽  
Lubrication Performance ◽  
Effect Of Surface

Surface texturing of the lubricated bearing has proven to improve the hydrodynamic performance. The present paper analyzed the effect of surface texturing on the covergent journal bearing with computational fluid dynamic (CFD) approach. The eccentricity ratio, the ratio of textured depth and surface area are the main parameter research. It was shown that for the eccentricity ratio of 0.2, the surface texturing improves the hydrodynamic performance lubrication by increasing the load support. On the otherwise, for the eccentricity ratio of 0.8, the surface texturing does not improve the lubrication performance, even under certain condition, it decreases the lubrication performance of journal bearing.

Effect of Surface Texturing on the Steady-State Properties and Dynamic Coefficients of a Plain Journal Bearing: Experimental Study

2011 ◽  
Author(s):  
Azzedine Dadouche ◽  
Martin J. Conlon ◽  
Waldemar Dmochowski ◽  
Waldemar Koszela ◽  
Lidia Galda ◽  
...  
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Surface Texturing ◽  
Spherical Shape ◽  
Journal Bearings ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Dynamic Coefficients ◽  
Internal Surfaces ◽  
Effect Of Surface

The last decade has seen a significant and increased interest in surface texturing technologies esulting in improving the overall tribological properties of mechanical components. Several techniques could be used to modify the surface topography with laser surface texturing becoming most popular recently. In this investigation, rig experiments have been performed on plain and textured-surface journal bearings with an aspect ratio of 1.1 under a variety of loads and speeds. Percussive burnishing (embossing) was used to create the dimples on the internal surfaces of the test bearings. The dimples have a spherical shape with a diameter of 1 mm and a depth of 60 micrometers. Pit-area ratio was in the range 5–20% of the total bearings surfaces. The effects of surface-texturing and dimple density on the bearing steady-state characteristics and dynamic coefficients are analyzed and discussed in this paper.

Analysis of Whirling Vibration Due to Morton Effect by Using Frequency Transfer Function Model in Journal Bearings

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Shota Yabui ◽  
Jotaro Chiba ◽  
Takafumi Suzuki ◽  
Shigeyuki Tomimatsu ◽  
Tsuyoshi Inoue
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Rotating Machinery ◽  
Rotating Shaft ◽  
Control Engineering ◽  
Proposed Model ◽  
Bending Mode ◽  
Morton Effect

Abstract In recent years, rotating machinery has been required to operate at high rotational speeds for high efficiency. However, with increase in the rotational speed, the rotating machinery may become unstable. One cause of unstable vibrations is the Morton effect that occurs in journal bearings. Thus, developing a mathematical model to predict the Morton effect is desirable to avoid the occurrence of such unstable vibrations. In this study, a model based on a frequency response that can quantitatively evaluate the Morton-effect-induced vibrations in rotating machinery supported by a journal bearing was developed. Experimental data were collected for modeling by using an experimental rig. Using the experimental data pertaining to the journal position in the journal bearing and temperature of the journal, a model for the Morton effect was established based on the frequency responses. From a control engineering viewpoint, the journal bearing was considered to be a proportional differential controller. In addition, the Morton-effect-induced vibrations were considered as a new bending mode of a rotating shaft, caused by thermal differences. Subsequently, the developed model was evaluated in the frequency domain. The characteristics of the vibrations, determined using the proposed model, exhibited good correlation with those corresponding to experimental data. The experimental data agreed well with the predicted results, and the results demonstrated the usefulness of the proposed method for predicting the Morton effect.

Numerical optimization of surface texture for improved tribological performance of journal bearing at varying operating conditions

2018 ◽  
Vol 70 (9) ◽  
pp. 1608-1618 ◽  
Author(s):  
Ali Usman ◽  
Cheol Woo Park
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Surface Texturing ◽  
Tribological Performance ◽  
Operating Conditions ◽  
Content Type ◽  
Load Carrying ◽  
Recent Developments ◽  
Effect Of Surface ◽  
Generalized Reynolds Equation

Purpose Journal bearings are used in numerous rotary machines. The load carrying capacity and friction of a bearing have been major concerns in design. Recent developments in surface texturing have showed potential outcomes to improve the tribological characteristics of mating surfaces. This study aims to investigate surface textures, which are transverse to the sliding direction, for frictional response of the journal bearing. Design/methodology/approach A hydrodynamic lubrication model is considered to evaluate the effect of surface texturing on the performance of a journal bearing at varying operating conditions. The two-dimensional generalized Reynolds equation, coupled with mass-conserving Elrod cavitation algorithm, is solved to evaluate texture-induced variations in tribological performance parameters. Findings Results have showed remarkable improvements in frictional response. Moreover, micro-textures on the journal surface alter the cavitation response and film-reformation in the hydrodynamic conjunction of the plain bearing. Originality/value Operating condition-based comprehensive exhaustive optimization of texture geometry is performed to generate widespread conclusion.

Effect of surface texturing on the dynamic characteristics of hydrodynamic journal bearing comprising concepts of green tribology

2018 ◽  
Vol 232 (11) ◽  
pp. 1365-1376 ◽  
Author(s):  
Shivank Matele ◽  
KN Pandey
Keyword(s):  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Surface Texturing ◽  
Stability Margin ◽  
Journal Bearings ◽  
Textured Surface ◽  
Viable Option ◽  
Hydrodynamic Journal Bearing ◽  
Green Tribology ◽  
Effect Of Surface

Surface texturing has emerged as a viable option for enhancing the surface properties. The present study analyzes the effect of full and partial micro-textured surface, at different locations and different kinds of dimple geometries, on the dynamic characteristics of hydrodynamic journal bearings and made a comparative study with the non-textured bearings. Three different kinds of dimple geometries, namely, circular texture, square texture, and densely distributed square texture have been adopted for study. The important dynamic characteristics of bearings were evaluated and stability charts were plotted. Location of the texture was found as an important parameter for improved dynamic characteristics though the extent of improvement depends largely on the geometry of texture. The partial textured bearing with proper geometry and location was found to be more stable. Stability margin of such bearings was more in comparison to the plain journal bearings and the relative improvement was found to be the maximum for circular texture and minimum for square texture. The study also shows the potential of surface texturing to make contribution in the accomplishment of the objectives of green tribology.

Effect of surface texturing on tribological performance of sliding guideway under boundary lubrication

2019 ◽  
Vol 47 ◽  
pp. 172-182 ◽  
Author(s):  
Hongzhi Yue ◽  
Jianxin Deng ◽  
Dongliang Ge ◽  
Xuemu Li ◽  
Yun Zhang
Keyword(s):  
Boundary Lubrication ◽  
Surface Texturing ◽  
Tribological Performance ◽  
Effect Of Surface

scholarly journals The Effect of Surface Texturing on Dry Gross Fretting

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 92 ◽  
Author(s):  
Agnieszka Lenart ◽  
Pawel Pawlus ◽  
Slawomir Wos ◽  
Andrzej Dzierwa
Keyword(s):  
Friction And Wear ◽  
Surface Texturing ◽  
Tribological Performance ◽  
Disc Surface ◽  
Abrasive Jet Machining ◽  
Wear And Friction ◽  
Steel Disc ◽  
Disc Configuration ◽  
Effect Of Surface ◽  
Ball On Disc

The effect of steel disc surface texturing on dry gross fretting in a ball-on-disc configuration was studied. Dimples were created with abrasive jet machining. The tribological performance of sliding pairs, steel–steel and steel–ceramics, was experimentally studied. The character of surface texturing effect was related to the dominant wear type. During steel–steel contact, the presence of dimples on disc surfaces could lead to increases in wear and friction. However, the escape of wear debris into dimples could result in reductions of friction and wear in the steel–ceramics configuration.

Numerical study on steady state performance enhancement of partial textured hydrodynamic journal bearing

2019 ◽  
Vol 71 (9) ◽  
pp. 1055-1063 ◽  
Author(s):  
Sanjay Sharma ◽  
Gourav Jamwal ◽  
R.K. Awasthi
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Performance Enhancement ◽  
Surface Texturing ◽  
Journal Bearings ◽  
Enhancement Ratio ◽  
Content Type ◽  
Maximum Value ◽  
Static Performance ◽  
Hydrodynamic Journal Bearing

Purpose The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For this, the bearings inner surface is textured with triangular shape with different texture depths and a number of textures in pressure increasing region. The textured region acts as a lubricant reservoir, which provides additional film-thickness and reduce friction. Therefore, enhance the overall performance of bearing. Design/methodology/approach In the present study, the effect of triangular shaped texture on the static performance characteristics of a hydrodynamic journal bearing has been studied. Different values of texture depths and a number of textures have been numerically simulated in pressure developing region. The static performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous Newtonian fluid. The performance enhancement ratio, which is the ratio of load carrying capacity (LCC) to the coefficient of friction (COF) has been calculated from results to finalized optimum design parameters. Findings The paper provides numerically obtained results indicate that surface texturing can improve bearing performance if the textured region is placed in the pressure increasing region. Moreover, surface texturing is the most effective at bearing performance enhancement when the bearing operates at lower eccentricity ratios and texture depth. The performance enhancement ratio, which is the ratio of LCC to the COF is found to be a maximum value of 2.198 at texture depth of 1.5, eccentricity ratio of 0.2 and the textured region located in the increasing pressure region. Research limitations/implications The present study is based on a numerical based research approach, which has its limitations. So, researchers are encouraged to investigate the same work experimentally. Practical implications The paper includes implications to be beneficial for designers for designing better hydrodynamic journal bearings. Originality/value For the triangular shaped texture, considered in the present study, the optimum values of texture depth and texture distribution region have also been determined. While designing, designers should focus on those values of texture depth, texture region and a number of textures, which give the maximum value of performance enhancement ratio, which represents maximum LCC at the lowest value of the COF.

A Numerical Solution for the Incompressible Hybrid Journal Bearing With Cavitation

1969 ◽  
Vol 91 (3) ◽  
pp. 508-515 ◽  
Author(s):  
Stanley Heller ◽  
Wilbur Shapiro
Keyword(s):  
Vapor Pressure ◽  
Pressure Gradient ◽  
Numerical Solution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Supply Circuit ◽  
Hydrodynamic Bearing

A numerical solution is presented for determining performance for hybrid journal bearings with arbitrary clearance distribution and cavitation. Regions of cavitation are determined by solution of the incompressible Reynolds’ equation. The pressures in the cavitated regions are immediately adjusted to a specified vapor pressure with zero pressure gradient. The continuity of mass equation permits coupling the influence of the external supply circuit and the methods of recess compensation to the Reynolds’ equation. Results are presented for geometrically similar hydrodynamic, hydrostatic, and hybrid bearings. Favorable comparisons are made with previously published results for the hydrodynamic bearing.

Load-Carrying Capacity Analysis for Sinusoidal Surfaces Hydrodynamic Bearing

2011 ◽  
Vol 295-297 ◽  
pp. 1244-1250
Author(s):  
Jian Xi Yang ◽  
Fa Yu Zhang ◽  
Jian Ting Liu ◽  
Jian Fang Zhou
Keyword(s):  
Carrying Capacity ◽  
Journal Bearing ◽  
Mathematic Model ◽  
Journal Bearings ◽  
Capacity Analysis ◽  
Load Carrying Capacity ◽  
Hydrodynamic Bearing ◽  
Load Carrying ◽  
Hydrodynamic Journal Bearing ◽  
Sinusoidal Surface

To obtain a new method to improve hydrodynamic bearing carrying capacity, hydrodynamic journal bearing’s characteristics as well as the current study direction are analyzed. According to the calculation of general cylindrical hydrodynamic journal bearing, the mathematic model for sinusoidal surface hydrodynamic bearing’s carrying capacity is established. It is used to calculate, analyze and compare these two bearings’ carrying capacity with example. The bearing, which has the characteristic of sinusoidal surface, has stronger carrying capacity than general cylindrical hydrodynamic bearing. What’s more, the improvement is more obvious when the number of waves is 3, also it has wider carrying area. Compared with other journal bearings, the journal bearing with sinusoidal surfaces has stronger carrying capacity, smaller friction moment and longer life-span. Therefore, it has extensive prospect.

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