A study on diesel engine crankshaft bearing failure analysis with consideration of bearing lubrication

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qi Liu ◽  
Baiqi Huo ◽  
Yunsheng Liu ◽  
Junchao Zhu
Keyword(s):  
Diesel Engine ◽  
Failure Mechanism ◽  
Working Condition ◽  
Mixed Lubrication ◽  
Bearing Failure ◽  
Content Type ◽  
Lubrication Performance ◽  
Lubrication Characteristics ◽  
The Relationship ◽  
Engine Crankshaft

Purpose The edge of diesel engine crankshaft main bearing is more likely to fail in its real working condition. This paper aims to study the bearing failure mechanism by finding the relationship between bearing lubrication characteristics and its working condition. Design/methodology/approach This work builds the mixed lubrication model of crankshaft bearing to analyze the cause of bearing abnormal wear, and the finite difference method was used to solving the average Reynolds equation. During the analysis, journal misaligned angle, external load and roughness are considered. Findings The result shows that the wear of the diesel engine crankshaft bearing happens in engine startup phase and the bottom of the bearing are more prone to be excessively worn. Under the influence of journal misalignment, bearing asperity contact load and speed range of mixed lubrication will increase markedly. The edge of the bearing will be excessively worn. The effect of misalignment on bearing lubrication performance varies under different shaft rotation speed. Originality/value The former research studies on crankshaft bearing either just focused on its lubrication characteristics or interested in its failure types (wear, adhere, cavitation). This paper studies the relationship between bearing failure mechanism and lubrication performance.

Effect of recess depth on lubrication performance of annular recess hydrostatic thrust bearing by constant rate flow

2018 ◽  
Vol 70 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jun-peng Shao ◽  
Guang-dong Liu ◽  
Xiao-dong Yu ◽  
Yan-qin Zhang ◽  
Xiu-li Meng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Simulation Method ◽  
Content Type ◽  
Oil Film ◽  
Constant Rate ◽  
Lubrication Performance ◽  
Optimal Value ◽  
Improved Performance ◽  
Lubrication Characteristics ◽  
Volume Method

Purpose The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow. Design/methodology/approach The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method. Findings The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing. Originality/value The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

Effect of piston clearance on the lubrication performance in axial piston pump

2019 ◽  
Vol 72 (1) ◽  
pp. 146-150
Author(s):  
Bora Lee ◽  
Yonghun Yu ◽  
Yong-Joo Cho
Keyword(s):  
Reynolds Equation ◽  
Design Method ◽  
Contact Region ◽  
Content Type ◽  
Piston Cylinder ◽  
Leakage Flow Rate ◽  
Lubrication Performance ◽  
Secondary Motion ◽  
Lubrication Characteristics ◽  
Axial Piston

Purpose This paper aims to provide a reliable and efficient numerical piston–cylinder design method and assess the effect of clearance on the piston-cylinder lubrication. Design/methodology/approach Numerical analyses of lubrication characteristics were performed for the piston–cylinder interface. The axial piston was numerically modeled, and the film pressure was calculated using the unsteady two-dimensional Reynolds equation. The behavior of the piston was analyzed by calculating the eccentricity satisfying the force and moment balance. Findings The secondary motion of the piston included numerically simulated several cycles until the piston behavior converged, and contact with the inner wall of the cylinder and friction region was estimated. Results showed that the piston–cylinder clearance affected the contact force, length of the contact region and leakage flow rate. Originality/value This result improves the understanding of the piston–cylinder lubrication and suggests considerations in terms of lubrication in clearance design.

An EHD-mixed lubrication analysis of main bearings for diesel engine based on coupling between flexible whole engine block and crankshaft

2015 ◽  
Vol 67 (2) ◽  
pp. 150-158 ◽  
Author(s):  
Lidui Wei ◽  
Haijun Wei ◽  
Shulin Duan ◽  
Yu Zhang
Keyword(s):  
Diesel Engine ◽  
Flow Model ◽  
Mixed Lubrication ◽  
Engine Block ◽  
Contact Theory ◽  
Asperity Contact ◽  
Block Model ◽  
Content Type ◽  
Oil Film ◽  
Average Flow Model

Purpose – The purpose of this paper is to develop a good calculation model to accurately predict the lubrication characteristic of main bearings of diesel engine and improve the service life. Design/methodology/approach – Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the Component Mode Synthesis (CMS) method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an elastohydrodynamic (EHD)-mixed lubrication model of the main bearings for the diesel engine is developed and researched with the finite volume method and the finite element method. Findings – Obviously, the mixed lubrication of bearings is normal, while full hydrodynamic lubrication is transient. The results show that under the whole flexible block model, maximum oil film pressure, maximum asperity contact pressure and radial shell deformation decrease, while minimum oil film thickness increases. Oil flow over edge decreases, and so does friction loss. Therefore, coordination deformation ability of whole engine block is favorable to mean load. In the whole block model, friction contact happens on both upper shell and lower shell positions. In addition, average oil film fill ratio at the key position becomes smaller in the whole engine block model, and consequently increases the chances of cavitations erosion more. So, wearing resistance of both upper and lower shells and anti-cavitations erosion ability must be enhanced simultaneously. Originality/value – Based on the coupling of the whole flexible engine block and the flexible crankshaft reduced by the CMS method, considering mass-conserving boundary conditions, the average flow model equation and Greenwood/Tripp asperity contact theory, an EHD-mixed lubrication model of the main bearings for the diesel engine is built, which can predict the lubrication of journal bearings more accurately.

Experimental investigation on the friction and sealing characteristics of narrow end-face seal ring with spiral grooves for wet clutch

2015 ◽  
Vol 67 (3) ◽  
pp. 240-245 ◽  
Author(s):  
Ji Bin Hu ◽  
Chao Wei ◽  
XueYuan Li
Keyword(s):  
Leakage Rate ◽  
Mixed Lubrication ◽  
Seal Ring ◽  
Face Seal ◽  
Test Volume ◽  
Content Type ◽  
Lubrication Performance ◽  
Wet Clutch ◽  
Rate Test ◽  
Spiral Grooves

Purpose – The purpose of this paper is to investigate the friction and sealing characteristics of narrow end face seal ring with spiral grooves for wet clutch by experiment. Design/methodology/approach – The shallow spiral grooves are machined in the end face of narrow seal ring by laser, and all of other parameters of specimens are the same with the actual production. The investigation of friction and sealing characteristics are carried out by comparing the experiment results of end face seal ring with spiral grooves with the conventional seal ring without spiral grooves through friction coefficient test, volume leakage rate test and pv value test. Findings – Comparing with conventional seal ring without spiral grooves, seal ring with spiral grooves experiences boundary lubrication, mixed lubrication and fluid film lubrication with the increase of rotation speed, whereas the conventional seal ring only experiences mixed lubrication. Besides this, the volume leakage rate is slightly larger, but the pv value is much larger than that of conventional seal ring. Originality/value – Effect of spiral grooves on the friction and sealing characteristics of narrow end face seal ring for wet clutch is investigated. The improved lubrication performance can be achieved by shallow spiral grooves even if the distance of radius difference used to machine grooves is very small.

Effect of grooved cylinder liner depths on the tribological performances of cylinder liner-piston ring

2019 ◽  
Vol 72 (3) ◽  
pp. 465-471
Author(s):  
Chao Zhen Yang ◽  
Zhiwei Guo ◽  
Changkun Xu
Keyword(s):  
Diesel Engine ◽  
Design Methodology ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Content Type ◽  
Sealing Performance ◽  
Lubrication Performance ◽  
Highly Correlated ◽  
Cylinder Liners ◽  
Groove Texture

Purpose Frictions in cylinder liner-piston ring often cause an inevitable loss of energy loss in the diesel engine. This study aims at evaluating the effect of depths in the cylinder liner groove texture on friction, wear and sealing performances. Design/methodology/approach Five depths of groove texture cylinder liners (50, 100, 150, 200, 250 µm) were fabricated, and experiments were carried out using a special-purpose diesel engine tester. Comparative analyses of cylinder liner contact resistances, piston ring wear losses and surface appearances were conducted with respect to different surface textures and applied loads. Findings Under no-load conditions, the cylinder liner with a 100 deep thread groove can significantly improve sealing and optimize its lubrication performance. On the other hand, the sealing is highly correlated with the depth of groove and the load within the cylinder liner. Under loaded conditions, the thread groove has less effect on the sealing performance. Originality/value The findings can provide feasible basis for the tribological design and production of diesel engines.

Effect of surface roughness, viscosity-pressure relationship and elastic deformation on lubrication performance of misaligned journal bearings

2014 ◽  
Vol 66 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Jun Sun ◽  
Xinlong Zhu ◽  
Liang Zhang ◽  
Xianyi Wang ◽  
Chunmei Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Elastic Deformation ◽  
Journal Bearing ◽  
Pressure Effect ◽  
Journal Bearings ◽  
Bearing Surface ◽  
Compliance Matrix ◽  
Content Type ◽  
Lubrication Performance ◽  
Lubrication Characteristics

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.

Virtual Texturing: Modeling the Performance of Lubricated Contacts of Engineered Surfaces

2005 ◽  
Vol 127 (4) ◽  
pp. 722-728 ◽  
Author(s):  
Q. Jane Wang ◽  
Dong Zhu
Keyword(s):  
Surface Design ◽  
Surface Textures ◽  
Design And Optimization ◽  
Lubricated Contacts ◽  
Influence Area ◽  
Lubrication Performance ◽  
Machine Elements ◽  
Lubrication Characteristics ◽  
Engineering Practices ◽  
The Relationship

Engineering practices and analyses have indicated that surface textures and topography may significantly affect the tribological performance of contact interfaces. Such an influence may be complicated and difficult to be captured with only a few statistic surface parameters. The need for further improvement of the performance and life of machine elements requires that surface topography and textures be optimized. The utilization of a numerical tool to determine the basic geometric aspects of surface textures may be named a virtual texturing technology, with which surface optimization may start from patterned surfaces where topography can be precisely quantified and the relationship between textures and lubrication performance can be numerically established. Presented in this paper are the concept of the virtual texturing technology, models involved, and a preliminary exploration of the relationship between a dimpled texture design and the mixed lubrication characteristics for a typical counterformal contact. The dimple influence area and the number of interruption are found to be two key factors for designing dimpled surfaces for counterformal contact lubrication. It is demonstrated that virtual texturing is able to provide comparative information and directions for innovative surface design and optimization.

Role of burnout on job level, job satisfaction, and task performance

2017 ◽  
Vol 38 (5) ◽  
pp. 630-645 ◽  
Author(s):  
Won Ho Kim ◽  
Young-An Ra ◽  
Jong Gyu Park ◽  
Bora Kwon
Keyword(s):  
Job Satisfaction ◽  
Task Performance ◽  
Organizational Context ◽  
Content Type ◽  
Job Level ◽  
Mediating Role ◽  
Final Sample ◽  
The Relationship ◽  
And Task

Purpose The purpose of this paper is to examine the mediating role of burnout (i.e. exhaustion, cynicism, professional inefficacy) in the relationship between job level and job satisfaction as well as between job level and task performance. Design/methodology/approach The final sample included 342 Korean workers from selected companies. The authors employed the Hayes (2013) PROCESS tool for analyzing the data. Findings The results showed that all three subscales of burnout (i.e. exhaustion, cynicism, professional inefficacy) mediate the relationship between job level and job satisfaction. However, only two mediators (i.e. cynicism, professional inefficacy) indicated the mediating effects on the association between job level and task performance. Originality/value This research presented the role of burnout on the relationships between job level, job satisfaction, and task performance especially in South Korean organizational context. In addition to role of burnout, findings should prove helpful in improving job satisfaction and task performance. The authors provide implications and limitations of the findings.

Dave Snowden on KM and big data/analytics: interview with David J. Pauleen

2017 ◽  
Vol 21 (1) ◽  
pp. 12-17 ◽  
Author(s):  
David J. Pauleen
Keyword(s):  
Big Data ◽  
Data Analytics ◽  
Big Data Analytics ◽  
Theory And Practice ◽  
Content Type ◽  
Face To Face ◽  
The Relationship ◽  
A Company ◽  
Practical Implications ◽  
Scientific Officer

Purpose Dave Snowden has been an important voice in knowledge management over the years. As the founder and chief scientific officer of Cognitive Edge, a company focused on the development of the theory and practice of social complexity, he offers informative views on the relationship between big data/analytics and KM. Design/methodology/approach A face-to-face interview was held with Dave Snowden in May 2015 in Auckland, New Zealand. Findings According to Snowden, analytics in the form of algorithms are imperfect and can only to a small extent capture the reasoning and analytical capabilities of people. For this reason, while big data/analytics can be useful, they are limited and must be used in conjunction with human knowledge and reasoning. Practical implications Snowden offers his views on big data/analytics and how they can be used effectively in real world situations in combination with human reasoning and input, for example in fields from resource management to individual health care. Originality/value Snowden is an innovative thinker. He combines knowledge and experience from many fields and offers original views and understanding of big data/analytics, knowledge and management.

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