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Article
Publication date: 18 August 2023

Max Marian

253

Abstract

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Industrial Lubrication and Tribology, vol. 75 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 26 November 2018

Stephan Tremmel, Max Marian, Michael Zahner, Sandro Wartzack and Marion Merklein

This paper aims to derive tailor-made microtextures for elastohydrodynamically lubricated (EHL) contacts under consideration of manufacturing possibilities.

235

Abstract

Purpose

This paper aims to derive tailor-made microtextures for elastohydrodynamically lubricated (EHL) contacts under consideration of manufacturing possibilities.

Design/methodology/approach

Component tests were used for the evaluation of the influence of surface texturing on the friction behavior in the cam/tappet contact. Furthermore, the manufacturing possibilities and limitations of a combined μEDM and micro-coining process and the feasibility of integration into a forming process were studied. Finally, a methodology based on transient EHL simulations and a meta-model of optimal prognosis was exemplarily used for microtexture optimization.

Findings

It was found that surface texturing in EHL contacts with high amount of sliding is promising. Moreover, the combination of μEDM and micro coining and the integration into established production processes allow the manufacturing of microtextures with desirable structural parameters and sufficient accuracy.

Originality/value

This paper gives a holistic view on surface microtexturing over several phases of the product life cycle, from the design, over efficient manufacturing to application-related testing.

Details

Industrial Lubrication and Tribology, vol. 71 no. 8
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 21 May 2024

Joseph Vivek, Naveen Venkatesh S., Tapan K. Mahanta, Sugumaran V., M. Amarnath, Sangharatna M. Ramteke and Max Marian

This study aims to explore the integration of machine learning (ML) in tribology to optimize lubrication interval decisions, aiming to enhance equipment lifespan and operational…

110

Abstract

Purpose

This study aims to explore the integration of machine learning (ML) in tribology to optimize lubrication interval decisions, aiming to enhance equipment lifespan and operational efficiency through wear image analysis.

Design/methodology/approach

Using a data set of scanning electron microscopy images from an internal combustion engine, the authors used AlexNet as the feature extraction algorithm and the J48 decision tree algorithm for feature selection and compared 15 ML classifiers from the lazy-, Bayes and tree-based families.

Findings

From the analyzed ML classifiers, instance-based k-nearest neighbor emerged as the optimal algorithm with a 95% classification accuracy against testing data. This surpassed individually trained convolutional neural networks’ (CNNs) and closely approached ensemble deep learning (DL) techniques’ accuracy.

Originality/value

The proposed approach simplifies the process, enhances efficiency and improves interpretability compared to more complex CNNs and ensemble DL techniques.

Details

Industrial Lubrication and Tribology, vol. 76 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 April 2023

Marlene Kristin Ziegler, Benedict Rothammer, Marcel Bartz, Sandro Wartzack, Patrick Beau, Gregor Patzer, Stephan Henzler and Max Marian

The evaluation of the haptics of water taps and wear-related changes during usage usually involves time- and cost-intensive testing. The purpose of this paper is to abstract the…

75

Abstract

Purpose

The evaluation of the haptics of water taps and wear-related changes during usage usually involves time- and cost-intensive testing. The purpose of this paper is to abstract the tribo-system between technical ceramic disks of water tap mixer cartridges to the model level and study the tribological behavior.

Design/methodology/approach

The friction and wear behavior was studied by means of an alumina ball-on-original alumina disk setup at different temperatures as well as under dry conditions and under lubrication by different greases. Thereby, the frictional behavior was measured in situ, and the wear losses were analyzed by means of laser scanning microscopy.

Findings

It was shown that friction and wear can behave in a contrasting way, whereby one grease might lead to low friction, that is, an easy-going movability of the water tap, but to increased wear losses. The latter, in turn, is an indicator for the usability and service life, which cannot be explained from friction alone. Thereby, the viscosity of the base oil, the grease consistency and additives were identified as relevant grease formulation parameters to allow for fluid film (re-)formation and removal of wear particles.

Originality/value

To the authors’ best knowledge, this is the first approach to systematically analyze the friction and wear behavior of technical ceramic disks of water tap mixer cartridges in dependency on the temperature as well as the used lubricating grease. This approach is relevant for developing screening test strategies as well as for the selection of lubricants for water tap applications.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2022-0334/

Details

Industrial Lubrication and Tribology, vol. 75 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 31 January 2023

Christian Orgeldinger, Tobias Rosnitscheck and Stephan Tremmel

Microtextured surfaces can reduce friction in tribological systems under certain contact conditions. Because it is very time-consuming to determine suitable texture patterns…

66

Abstract

Purpose

Microtextured surfaces can reduce friction in tribological systems under certain contact conditions. Because it is very time-consuming to determine suitable texture patterns experimentally, numerical approaches to the design of microtextures are increasingly gaining acceptance. The purpose of this paper is to investigate to what extent the selected modeling approach affects optimized texturing.

Design/methodology/approach

Using the cam/tappet contact as an application-oriented example, a simplified 2D and a full 3D model are developed for determining the best possible texturing via a design study. The study explores elongated Gaussian-shaped texture elements for this purpose. The optima of the simplified 2D simulation model and the full 3D model are compared with each other to draw conclusions about the influence of the modeling strategy. The target value here is the solid body friction in contact.

Findings

For the elongated texture elements used, both the simplified 2D model and the full model result in very similar optimal texture patterns. In the selected application, the simplified simulation model can significantly reduce the computational effort without affecting the optimization result.

Originality/value

Depending on the selected use case, the simulation effort required for microtexture optimization can be significantly reduced by comparing different models first. Therefore, an exact physical replica of the real contact is not necessarily the primary goal when it comes to texture selection based on numerical simulations.

Details

Industrial Lubrication and Tribology, vol. 75 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 23 June 2023

Ferdinand Schmid, Constantin Paschold, Thomas Lohner and Karsten Stahl

Internal gearings are commonly used in transmissions due to their advantages like high-power density. To ensure high efficiency, load-carrying capacity and good noise behavior, a…

740

Abstract

Purpose

Internal gearings are commonly used in transmissions due to their advantages like high-power density. To ensure high efficiency, load-carrying capacity and good noise behavior, a profound knowledge of the local gear mesh is essential. The tooth contact of internal gears relates to a convex and concave surface that form a conformal contact. This is in contrast to external gears, where two convex surfaces form a contraformal contact. This paper aims at a better understanding of conformal contacts under elastohydrodynamic lubrication (EHL) to improve the design of internal gearings.

Design/methodology/approach

An existing numerical EHL model is used for studying the characteristic properties of a hard conformal EHL line contact. A hard contraformal EHL line contact is studied as reference. Non-Newtonian fluid behavior and thermal effects are considered. By taking into account the local contact conformity and kinematics, the effects and relevance of the curvature of the lubricant gap and micro-slip are analyzed. In a parameter study, scale effects of the contact radii on film thickness, temperature rise and friction are examined.

Findings

The curvature of the lubricant gap and effects of micro-slip are small in hard conformal EHL line contacts. For high micro-slip, it can be neglected. Hence, the modeling of conformal contacts using an equivalent geometry of the contact problem is reasonable. The parameter study shows beneficial tribological aspects of the conformal contact compared to the contraformal contact. Higher film thickness and lower fluid coefficient of friction are observed for conformal contacts, which can be attributed to lower pressures for the case of the same external normal force, or to a higher contact temperature rise for the case of equivalent contact pressure.

Originality/value

Despite its widespread existence, the local geometry and kinematics in hard conformal EHL line contacts like in internal gearings have been rarely studied. The findings help for a better understanding of local contact characteristics and its relevance. The quantified scale effects help to improve the efficiency and load-carrying capacity of machine elements with hard conformal EHL contacts, like internal gearings.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2022-0366/

Details

Industrial Lubrication and Tribology, vol. 75 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 15 January 2018

Krzysztof Kasianiuk

This paper aims to provide introductory conceptual tools for studying political power in a complex multi-level environment. In particular, it is intended to answer the question of…

249

Abstract

Purpose

This paper aims to provide introductory conceptual tools for studying political power in a complex multi-level environment. In particular, it is intended to answer the question of how concepts provided by cybernetics and general systems theory (GST) could serve to foster the study of political power.

Design/methodology/approach

The objective is realized through a reconsideration of a set of the basic concepts of cybernetics, GST and political science. Two system identification models – black box and white box – along with Marian Mazur’s concept of steering are used to deconstruct the classic definition of power formulated by Max Weber. Next, a two-phase procedure for empirical power analysis is proposed. Rudimentary in its scope, the article shows a path of more comprehensive and transformative analyses of key notions.

Findings

It seems that system identification models help uncover structural and functional aspects of political power, which aids the process of analysis of different mechanisms of political power.

Originality/value

The article supports the argument for a conceptual isomorphism between cybernetics and political science. The value of the proposed approach is derived from the combination of two features. First, two aspects of system operation – functional and structural – help to focus research attention on different problems of political power analysis. Second, the interrelation and interdependence of both aspects of systems operation serve as a practical means in the analysis of communication and behavior of actors in the political power processes.

Details

Kybernetes, vol. 47 no. 6
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 12 November 2021

Fuqin Yang, Xiaojie Han and Mingqing Si

This paper aims to study the influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the thermal elastohydrodynamic…

90

Abstract

Purpose

This paper aims to study the influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the thermal elastohydrodynamic lubrication (TEHL) characteristics and optimisation of the ball-type tripod universal joint.

Design/methodology/approach

The point contact TEHL model of the joint was developed, and the multi-grid method was used to solve it. The influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the lubrication characteristics was analysed. Further, the optimisation of the joint TEHL performance was carried out by the Kriging approximation model combined with the multi-objective particle swarm optimisation (MOPSO) algorithm.

Findings

The research results show that increasing groove shell radius and ball radius can effectively increase the oil film thickness, and decrease the oil film pressure, as well as the temperature rise. Decreasing elastic modulus can reduce the oil film temperature rise and pressure, and increasing viscosity can effectively increase the oil film thickness. The optimised minimum oil film thickness increases by 33.23% and the optimised maximum oil film pressure and maximum temperature rise decrease by 11.92% and 28.87%, respectively. Furthermore, the relative error of each response output is less than 10%.

Originality/value

This study applies TEHL theory to the tribological research of the ball-type tripod universal joint, and the joint’s lubrication performance is improved greatly by the Kriging model and MOPSO algorithm, which provides an effective measure to raise the joint’s working efficiency.

Details

Industrial Lubrication and Tribology, vol. 73 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 15 September 2023

Deepak Kumar Prajapati, Jitendra Kumar Katiyar and Chander Prakash

This study aims to use a machine learning (ML) model for the prediction of traction coefficient and asperity load ratio for different surface topographies of non-conformal rough…

257

Abstract

Purpose

This study aims to use a machine learning (ML) model for the prediction of traction coefficient and asperity load ratio for different surface topographies of non-conformal rough contacts.

Design/methodology/approach

The input data set for the ML model is generated using a mixed-lubrication model. Surface topography parameters (skewness, kurtosis and pattern ratio), rolling speed and hardness are used as input features in the multi-layer perceptron (MLP) model. The hyperparameter tuning and fivefold cross-validation are also performed to minimize the overfitting.

Findings

From the results, it is shown that the MLP model shows excellent accuracy (R2 > 90%) on the test data set for making the prediction of mixed lubrication parameters. It is also observed that engineered rough surfaces with high negative skewness, low kurtosis and isotropic surface patterns exhibit a significant low traction coefficient. It is also concluded that the MLP model gives better accuracy in comparison to the random forest regression model based on the training and testing data sets.

Originality/value

Mixed lubrication parameters are predicted by developing a regression-based MLP model. The machine learning model is trained using several topography parameters, which are vital in the mixed-EHL regime because of the lack of regression-fit expressions in previous works. The accuracy of MLP with random forest models is also compared.

Details

Industrial Lubrication and Tribology, vol. 75 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

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Book part
Publication date: 1 October 2018

Naomi Woodspring

Abstract

Details

Baby Boomers, Age, and Beauty
Type: Book
ISBN: 978-1-78743-824-8

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