Investigations on influence of groove shapes for the journal bearing in high-speed and heavy-load press system

2018 ◽  
Vol 70 (1) ◽  
pp. 230-240 ◽  
Author(s):  
Yu Chen ◽  
Yu Sun ◽  
Chunping Cao
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Journal Bearing ◽  
Computational Method ◽  
Hydrodynamic Characteristics ◽  
Hydrodynamic Behavior ◽  
Heavy Load ◽  
Content Type ◽  
Thermal Influence ◽  
Fluid Interaction

Purpose The purpose of this study is to investigate the hydrodynamic characteristics of journal bearings in a high-speed and heavy-load press system by considering thermal influence and cavitation. Design/methodology/approach A proper and effectual computational method is presented for steady-state analysis of fluid interaction in a rotor-bearing press system by combining computational fluid dynamics techniques. Findings The influences of eccentricity ratio, rotational speed and oil-film thickness on the hydrodynamic behavior of the journal bearing are studied. Originality/value The computational method can be used for creating a precise lubrication design for a journal bearing of a lubrication system.

Effect of recess configuration on the performances of high-speed hybrid journal bearing

2016 ◽  
Vol 68 (3) ◽  
pp. 301-307 ◽  
Author(s):  
Qiyin Lin ◽  
Zhengying Wei ◽  
Ning Wang ◽  
Yubin Zhang
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Design Methodology ◽  
High Stability ◽  
Journal Bearing ◽  
Content Type ◽  
Structure Interaction ◽  
Bearing Design ◽  
Effects Of Temperature ◽  
Interaction Approach

Purpose The purpose of this paper is to study the influences of recess configurations on the performances of high-speed hybrid journal bearing. Hybrid journal bearing earns increasing attention in high-speed machine tool spindle owing to its intrinsic outstanding performances of low temperature rise and high stability. Design/methodology/approach To investigate the coupled effects of temperature, turbulence and the interaction between lubricant and journal/bearing bush, a thermal fluid-structure interaction approach is presented and validated by the experimental results. Findings Ladder-type recess has excellent tribological characteristics in decreasing temperature rise, improving stability and inhibiting cavitation, which are all beneficial to improve the performances of high-speed spindle system. Originality/value This work can be a valuable guide for the future high-speed hybrid journal bearing design.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

Surfaces with pores: hydrodynamic lubrication

2017 ◽  
Vol 69 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Leonid Burstein
Keyword(s):  
Design Methodology ◽  
Hydrodynamic Lubrication ◽  
Dimensional Model ◽  
Hydrodynamic Behavior ◽  
Content Type ◽  
One Dimensional ◽  
Lubricating Film ◽  
Cell Dimensions ◽  
Practical Implications ◽  
Pore Cell

Purpose This paper aims to assess the hydrodynamic lubrication of two opposing surfaces with identical pores having a semicircular profile. The surfaces are treated with more than one pore that allows clarification of whether there exists interaction between the pores. Design/methodology/approach A transient, spatial, one-dimensional model of surfaces with regular pores was developed and applied in the context of fluid lubrication. MATLAB software has been used. Findings Calculations show that a lubricating film between two surfaces with pores provides better hydrodynamic conditions in comparison to that on one surface with pores. It was also shown that the pores of one surface act as separate objects and can take into account only the interaction between the pores of the opposite surfaces. In addition, it was found that there are optimum values of the pore radii, gap and pore cell dimensions at which the bearing capacity of the film is maximal. Practical implications The computer program used for the pore parameter calculations provided the optimal lubrication. Originality/value This is the first study of the lubricating film hydrodynamic behavior of two opposite surfaces with pores having a semicircular profile.

Control on wear of journal bearing operating in mixed lubrication regime using grooving arrangements

2016 ◽  
Vol 68 (4) ◽  
pp. 458-465 ◽  
Author(s):  
Lijesh K.P. ◽  
Muzakkir S.M. ◽  
Harish Hirani ◽  
Gananath Doulat Thakre
Keyword(s):  
Journal Bearing ◽  
Wear Behavior ◽  
Research Work ◽  
Theory Model ◽  
Mixed Lubrication ◽  
Experimental Investigations ◽  
Heavy Load ◽  
Content Type ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime

Purpose The journal bearings subjected to heavy load and slow speed operate in mixed lubrication regime causing contact between the interacting surfaces and resulting in wear. Complexity of wear behavior and lack of unifying theory/model make wear-control very challenging. Design/methodology/approach In the present research work, theoretical and experimental investigations have been conducted to explore the effect of grooving arrangements on the wear behavior of journal bearing operating in mixed lubrication regime. The theoretical model of Hirani (2005) that uses mass conserving cavitation algorithm has been used to determine the bearing eccentricity for different groove arrangements (with varying groove location and extent) for identifying a groove arrangement that minimizes the wear. The wear tests on the grooved bearings were conducted after suitable running-in of the new bearings on a fully automated journal bearing test set-up. A load and speed combination required to operate the bearing in mixed lubrication was used. The performance of different arrangement of bearing was evaluated by measuring their weight loss after the test. Findings Wear was significantly reduced with the use of proper groove arrangement for a bearing operating in mixed lubrication regime. Originality/value The improvement in bearing performance by providing grooves has been the subject matter of several studies in the past, but these studies were confined to the hydrodynamic operative regime of the bearing. In the present work, seven different combinations of axial and radial groove arrangement were tried, which has not been reported in any other work.

Linear stability analysis of finite hydrodynamic journal bearing under turbulent lubrication with coupled-stress fluid

2016 ◽  
Vol 68 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Abhishek Ghosh ◽  
Sisir Kumar Guha
Keyword(s):  
Stability Analysis ◽  
Newtonian Fluid ◽  
High Speed ◽  
Journal Bearing ◽  
Slenderness Ratio ◽  
Linear Perturbation ◽  
Content Type ◽  
Hydrodynamic Journal Bearing ◽  
The Stability ◽  
Coupled Stress

Purpose Several researchers have observed that to satisfy modern day’s need, it is essential to enhance the characteristics of journal bearing, which is used in numerous applications. Moreover, the use of Newtonian fluid as a lubricant is diminishing day by day, and the use of Non-Newtonian fluids is coming more into picture. Furthermore, if turbo-machinery applications are taken into account, then it can be seen that journal bearings are used for high speed applications as well. Thus, neglecting turbulent conditions may lead to erroneous results. Hence, this paper aims to present focuses on studying the stability characteristics of finite hydrodynamic journal bearing under turbulent coupled-stress lubrication. Design/methodology/approach First, the governing equation relevant to the problem is generated. Then, the dynamic analysis is carried out by linear perturbation technique, leading to three perturbed equations, which are again discretized by finite difference method. Finally, these discretized equations are solved with the help of Gauss-Seidel Iteration technique with successive over relaxation scheme. Consequently, the film response coefficients and the stability parameters are evaluated at different parametric conditions. Findings It has been concluded from the study that with increase in value of the coupled-stress parameter, the stability of the journal may increase. Whereas, with increase in Reynolds number, the stability of the journal decreases. On the other hand, stability increases with increasing values of slenderness ratio. Originality/value Researches have been performed to study the dynamic characteristics of journal bearing with non-Newtonian fluid as the lubricant. But in the class of non-Newtonian lubricants, the use of coupled-stress fluid has not yet been properly investigated. So, an attempt has been made to perform the stability analysis of bearings with coupled-stress fluid as the advanced lubricant.

Behaviour of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and micropolar lubricant

2017 ◽  
Vol 69 (6) ◽  
pp. 844-862 ◽  
Author(s):  
Chandra B. Khatri ◽  
Satish C. Sharma
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Technique ◽  
Surface Texturing ◽  
Textured Surface ◽  
Performance Parameters ◽  
Content Type ◽  
Fluid Theory ◽  
Bearing System

Purpose The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing. Design/methodology/approach In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique. Findings The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing. Originality/value The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.

Using fractional order weakening buffer operator to forecast the main indices of online shopping in China

2019 ◽  
Vol 9 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Xiao Hui Gao ◽  
Lifeng Wu
Keyword(s):  
Fractional Order ◽  
High Speed ◽  
Design Methodology ◽  
Online Shopping ◽  
Experimental Results ◽  
Order Number ◽  
Growth Trend ◽  
Content Type ◽  
Economic Indices ◽  
Expansion Period

Purpose The purpose of this paper is to predict the main economic indices of online shopping in China. Design/methodology/approach A fractional order weakening buffer operator (WBO) for the GM(1,1) model is put forward in order to solve the problem of limited nonlinear data. The order number of WBO can adjust in line with the scenario. Findings The experimental results indicate that the proposed method can consider the scenario and obtain more accurate forecasting results. Originality/value This study found that the slowdown of growth trend after the previous high speed expansion period will continue, and the online shopping sellers should make more efforts to develop potential consumers to increase its turnover.

Time pressure and improvisation: enhancing creativity, adaption and innovation at high speed

2015 ◽  
Vol 29 (6) ◽  
pp. 7-9 ◽  
Author(s):  
Josh Hodge ◽  
Vanessa Ratten
Keyword(s):  
Competitive Advantage ◽  
High Speed ◽  
Design Methodology ◽  
Time Pressure ◽  
Training Needs ◽  
Content Type

Purpose – Organizations are becoming more focused on time pressures when introducing innovation and creativity into their organizations. The purpose of this paper is to discuss the opportunity for organizations to focus on improvisation training as a way to gain a competitive advantage and leapfrog their competitors. Design/methodology/approach – This paper takes the approach of identifying a model of improvisation training for organizations that focuses on the convergence of planning and executive for promoting innovation training practices. Findings – This paper’s main findings are that the time pressures faced by organizations means that there is a funnel limiting the link between creativity, adaption and innovation. This means that improvisation training needs to be done quickly, and organizations need to act efficiently when introducing new practices. Originality/value – This paper’s key value is that organizations can use improvisers by using bricolage and ready-mades to take existing concepts and apply them to new situations.

A machine learning approach-based power theft detection using GRF optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
A. Prakash ◽  
A. Shyam Joseph ◽  
R. Shanmugasundaram ◽  
C.S. Ravichandran
Keyword(s):  
Machine Learning ◽  
Transmission Lines ◽  
High Speed ◽  
Design Methodology ◽  
Learning Approach ◽  
Smart Meter ◽  
Financial Loss ◽  
Content Type ◽  
Garra Rufa ◽  
Machine Learning Approach

Purpose This paper aims to propose a machine learning approach-based power theft detection using Garra Rufa Fish (GRF) optimization. Here, the analyzing of power theft is an important part to reduce the financial loss and protect the electricity from fraudulent users. Design/methodology/approach In this section, a new method is implemented to reduce the power theft in transmission lines and utility grids. The detection of power theft using smart meter with reliable manner can be achieved by the help of GRF algorithm. Findings The loss of power due to non-technical loss is small by using this proposed algorithm. It provides some benefits like increased predicting capacity, less complexity, high speed and high reliable output. The result is analyzed using MATLAB/Simulink platform. The result is compared with an existing method. According to the comparison result, the proposed method provides the good performance than existing method. Originality/value The proposed method gives good results of comparison than those of the other techniques and has an ability to overcome the associated problems.

Hardware simulation of lane keeping assist based on sensor fusion

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Noor Cholis Basjaruddin ◽  
Edi Rakhman ◽  
Fazrin Adinugraha
Keyword(s):  
Sensor Fusion ◽  
High Speed ◽  
Design Methodology ◽  
Human Error ◽  
Fusion Method ◽  
Safety Index ◽  
Content Type ◽  
Speed Mode ◽  
Lane Keeping ◽  
Important System

PurposeSafety is one of the most crucial factors in transportation due to so many factors, including human-error, that might result in various small to fatal accidents. This is why lane keeping assist (LKA) is an important system that needs to be developed. LKA will prevent the vehicle from moving to another lane because the driver is negligent to maintain the direction of the vehicle.Design/methodology/approachIn this study, LKA works using camera and ultrasonic sensors. The data coming from these two types of sensors are then fused to determine how should the car reacts to some certain situation so that it stays on the lane. The sensor fusion method was used to further ensure the car's safety.FindingsThe results of the hardware simulation show that LKA can successfully avoid the car from getting off the lane with safety index of 95% for high-speed mode and 100% for medium and low-speed mode; meanwhile on the use of ultrasonic sensor, the speed of the car is adjusted to the distance of the car's side disturbance.Originality/valueThis research has succeeded in simulating a sensor fusion–based LKA system.

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