Influence of Surface Texture Configuration and Depth on Tribological Performance of Hydrodynamic Journal Bearing

2012 ◽  
Vol 155-156 ◽  
pp. 318-323 ◽  
Author(s):  
Su Hua Wang ◽  
Jian Hua Zheng ◽  
Xin Yue Wu

A finite-difference numerical model is used to study the influence of surface textures configuration and depth on lubrication performance of hydrodynamic journal bearing. Reynolds equation is adopted to calculate the bearing dimensionless load carrying capacity, friction force and friction coefficient under different eccentricity ratio, textures configuration and depth. Results show that partial texturing in the inlet zone with shallow dimples and in the cavitation zone with deep dimples could improve bearing performance appreciably. The effect of the textures on bearing tribological performance was influenced by the eccentricity ratio. The advantage of partial textures decreases when the eccentricity ratio increases.

2011 ◽  
Vol 120 ◽  
pp. 426-431 ◽  
Author(s):  
Su Hua Wang ◽  
Xin Yue Wu ◽  
Jian Hua Zheng

A finite-difference numerical model is used to study the influence of surface texture on lubrication performance of hydrodynamic journal bearing. Reynolds equation is adopted to calculate the bearing load carrying capacity, friction force and friction coefficient under different width-diameter ratio, different eccentricity ratio and different texture location. Results show that partial texture along the circumferential direction on the bearing with small width-diameter ratio will increase bearing performance appreciably. Partial texture along the axial direction will decrease friction coefficient effectively, especially at the film inlet zone or the position of film pressure trending to zero.


Author(s):  
Niranjan Singh ◽  
RK Awasthi

This paper concerns with theoretical investigation to predict the influence of cylindrical textures on the static and dynamic performance characteristics of hydrodynamic journal bearing system and the performance is compared with smooth surface bearing. The Reynolds equation governing the fluid–film between the journal and the bearing surface is solved numerically with the assistance of finite element method and the performance characteristics are evaluated as a function of eccentricity ratio, dimple depth and its location. In this study, four journal bearing configurations viz: smooth (non-textured), full-textured, partially textured-I, and partially textured-II are considered for the evaluation of theoretical results. The simulated results indicate that the influence of surface textures is more significant when the textures were created in upstream zone of 126°–286° and dimple aspect ratio nearly 1.0.


2018 ◽  
Vol 159 ◽  
pp. 02042
Author(s):  
Mohammad Tauviqirrahman ◽  
Bayu Kurniawan ◽  
Jamari

Recently, a growing interest is given to the wall slip and the artificial texturing for improving the performance of lubricated sliding contact. The use of wall slip, artificial texturing, and the combination of slip and texturing can be the effective approach to enhance the performance of the bearing. The present study examines the effect of shaft eccentricity ratio on the hydrodynamic journal bearing performance. 3D numerical modelling based on modified Reynolds equation is used to analyse the effect of texturing and the wall slip on the characteristics of a hydrodynamically lubricated sliding contact. The analysis results point out that with respect to the load support and the power loss of the bearing, the use of wall slip on smooth surface is the most excellent configuration compared to other patterns (i.e. slip-texturing, pure texturing and conventional patterns). It is also confirmed that the wedge effect due to the shaft eccentricity has a significant role in altering the lubricant behaviour. Thus, a particular care must be taken in choosing the pattern of lubricated sliding contact as well as the shaft eccentricity.


1979 ◽  
Vol 101 (4) ◽  
pp. 444-450 ◽  
Author(s):  
V. Kamala

This paper analyzes the load-carrying capacity of the hybrid air lubricated journal bearing. Assuming a small eccentricity ratio, a first order perturbation solution is obtained. The air is fed to the bearing through inherent restrictor with feeding holes distributed around the circumference in one, two, and three feeding planes (Fig. 1). The number of feeding holes in each plane is sufficiently large to permit the feeding planes being treated as the line sources. The results are given for the load-carrying capacity and the attitude angle. A comparative study is made of the three types of gas feeding arrangements.


1970 ◽  
Vol 12 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. C. Majumdar

A theoretical investigation is made to predict the performance of an externally pressurized air journal bearing having several pressure sources. The pressure distribution, which leads to the determination of load-carrying capacity and flow requirement, is obtained by solving Reynolds equation numerically. The load and flow, expressed in non-dimensional parameters, are presented for different bearing design parameters (dimensionless). The results predicted by this method are compared with others' experimental data.


10.29007/pq98 ◽  
2018 ◽  
Author(s):  
Tushar Gundarneeya ◽  
Dipak Vakharia

In this work, influence of nanolubricants on the load carrying capacity of hydrodynamic journal bearing is studied. Increase in viscosity of lubricant oil with nanopartical as lubricant additives is modeled using different classical model and compared with Kriger-Doughetry viscosity model. This Kriger-Doughetry viscosity model for simulating viscosity of nanolubricant is validated by Experimental verification using reheometer. The pressure distribution and load carrying capacity are theoretically analyzed using Reynolds Equation for Reynolds boundary condition for different concentration of nanoparticles volume fraction. Result reveal increase in pressure and load carrying capacity of Journal bearing with nanolubricants in comparison to base oil.


Author(s):  
Ashutosh Kumar ◽  
Sashindra Kumar Kakoty

Abstract Static and dynamic performance parameters of two-lobe journal bearing, working with non-Newtonian lubricant has been obtained. Krieger-Dougherty model is used to obtain the effective viscosity of nano-lubricant for a given concentration of solid-particle in base lubricant. Modified Reynolds equation is solved to obtain bearing performance parameters for couple stress model and variable viscosity model. Dynamic coefficients are also determined for various couple stress parameter. Results reveal a noticeable increase in flow co-efficient and load carrying capacity while there is a decrease in friction variable. It also reveals a significant betterment in dynamic co-efficient of bearing.


Author(s):  
Biplab Bhattacharjee ◽  
Prasun Chakraborti ◽  
Kishan Choudhuri

The features of micropolar fluid (a non-Newtonian fluid)–lubricated short single-layered porous hydrostatic journal bearing are analyzed theoretically by an iterative method. To investigate hydrostatic journal bearing characteristics, a modified Reynolds equation in the case of micropolar fluid is derived and solved numerically. The obtained results in this work are validated by comparing the same with previously published results with Newtonian and non-Newtonian lubricants in the form of design charts. The static stiffness and load-carrying capacity of the investigated bearing are 80% and 75% higher than conventional hydrostatic bearings. The porous hydrostatic journal bearing exhibits more economical performance as it requires 40% low flow rate and low pump power, and it generates 50% less heat in contrast with other hydrostatic bearings.


Author(s):  
Boualem Chetti ◽  
Hamid Zouggar

In this work, a numerical study of the effect of elastic deformation on the static characteristics of a circular journal bearing operating with non-Newtonian fluids obeying to the power law model is presented. The modified Reynolds equation has been derived taking into consideration the effect of non-Newtonian behavior of the fluids. To obtain the pressure distribution, the Reynolds equation has been solved using finite difference technique with appropriate iterative technique incorporating Reynolds boundary conditions. The static performance characteristics for finite-width journal bearing in terms of the load-carrying capacity, the attitude angle, friction coefficient, and the side leakage have been studied for various values of the non-Newtonian power law index n and the elastic coefficient. The results show that the increase of the power law index produces a higher load-carrying capacity, a higher side leakage, a lower attitude angle, and a lower friction coefficient. From this study, it can be concluded that the elastic deformation has an important influence on the static characteristics of the journal bearing lubricated with a non-Newtonian fluid, and this influence is more significant for the journal bearing operating at larger values of the eccentricity ratio.


Author(s):  
B. Chetti

This work is an investigation of the performance characteristics of an offset journal bearing lubricated with a fluid with couple stresses taking into consideration the elastic deformation of the liner. The couple stresses might be expected to appear in noticeable magnitudes in liquids containing additives with large molecules. The modified Reynolds equation has been solved using the finite difference method. Load carrying capacity, attitude angle, side leakage and friction coefficients are determined for various values of couple stress parameter of a rigid and deformable bearing. It is found that, the static characteristics of journal bearings lubricated with couple stress fluids are improved compared to journal bearings lubricated with Newtonian fluids. It is concluded that, the elastic deformation of the bearing has significant influence on the bearing characteristics.


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