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Fundamentals of Design and Technology of Rolling Element Bearings

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Chinese Journal of Aeronautics 2010年第1期23卷 123-136页

作者： Franz-Josef Ebert FAG Aerospace gmbh & co.kg D-97421 SchweinfurtGermany

This article presents an overview of fundamentals of rolling element bearing designs and technologies. The aim is to outline the complex interrelation of all fundamentals with the rolling contact fatigue and the attainable bearing life. Such fundamentals include, amongst others, bearing stressing and life capability. The article shows the different types of rolling bearing stressing and the analysis of the stress distribution （principal stresses and equivalent stresses） in the material under the rolling contact area. It becomes obvious that the contamination of the bearing with foreign particles leads to a drastic reduction in bearing life. Furthermore, it demonstrates the impact of the bearing lubrication and coating as well as the effect of additives on the attainable life and wear. Further fundamentals of rolling element bearing de- sign are the materials, the material cleanliness and the heat treatment. The article reveals the importance of the clean- liness of bearing steels as well as different types of inclusions and their effect on rolling contact fatigue. Additionally the article describes how to optimize the material properties （strength, toughness and residual stress） by the heat treat- nlent processes. The outcome of these investigations is that endurance life of a rolling element bearing can be achieved if specific operating conditions, an adequate lubrication, good system cleanliness and specific bearing stressing are met. The article provides a guideline for bearing engineers on how designs and technologies can be applied to optimizing a bearing for a particular industry or aerospace application.

关键词： aerospace rolling contact fatigue endurance life materials heat treatment lubrication reliability

Integration of Gas Nitrocarburising and Oxidising in a Mass Production Line for Brake Pistons

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材料热处理学报 2004年第5期25卷 405-408页

作者： Gero Walkowiak Dieter Miiller Uwe Zeibig Bodycote Warmebehandlung gmbh Ebersbach GermanyBodycote Warmebehandlung GmbH Ebersbach GermanySander Umformtechnik GmbH & Co. KG Renchen-Ulm Germany

The combination of wear- and corrosion resistance is a demand to a multitude of automotive parts. Several metallic coatings as hard/soft chromium or electroless nickel have been the conventional surface protection e.g. on parts as brake pistons and shock absorber or gas spring piston rods. The corr-I-Dur* process - a special gasnitrocarburising and oxidising technology - has a huge potential not only in substituting those coatings but also in delivering surfaces with higher quality. The benefits of the replacement of soft chromium with corr-I-Dur and the implementation of the process in the customers production line with an annual capacity of 17 million brake pistons is described in this presentation. Starting with the demands on wear- and corrosion resistance the way of process development and the design of applicative equipment is shown. The result is a tailor-made surface solution with superior quality for deep drawn brake pistons. Two main disadvantages - outgassing of the chromium layer and reduced corrosion resistance on the inner diameter - are eliminated by the replacement with corr-I-Dur . The process-sure achievement of enhanced corrosion resistance, uniform layer thickness, negligible distortion as well as environmental and economical advantages make corr-I-Dur? an excellence choice for this application.

关键词：气体氮碳共渗氧化耐蚀性制动器汽缸活塞大量生产

An Overview of Performance Characteristics, Experiencesand Trends of Aerospace Engine Bearings Technologies

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Chinese Journal of Aeronautics 2007年第4期20卷 378-384页

作者： Ebert Franz-Josef Sales and Product Development Aerospace FAG Aerospace GmbH & Co. KG Schweinfurt D-97421 Germany

In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today＇s material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace gmbh ＆ co. kg is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.

关键词： aerospace engine bearing performance characteristic material technology integrated bearing design reliability system cost

Plants and Animals as concept Generators for the Development of Biomimetic Cable Entry Systems

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Journal of Bionic Engineering 2008年第2期5卷 167-173页

作者： Tom Masselter Uwe Scharf Thomas Speck Plant Biomechanics Group Botanic Garden of the University Freiburg Rittal gmbh & co.kg Auf dem SttzelbergHerborn D-35745Germany

Many animals and plants have high potential to serve as concept generators for developing biomimetic materials and structures. We present some ideas based on structural and functional properties of plants and animals that led to the development of two types ofbiomimetic cable entry systems. Those systems have been realized on the level of functional demonstrators.

关键词： bionics biomimetics cable entry stents folding structures

Failure analysis of a kind of low power connector

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 384-392页

作者： ZHOU Yi-lin ZENG Ning XU Liang-jun JORGENS Stefan Research Lab of Electric contacts Beijing University of Posts ＆ Telecommunications Beijing 100876 China Lumberg connect gmbh ＆ co. kg Schalksmiihle 58579 Germany

A kind of low power connector used e.g. in household appliances was partly burned in routine experiment. The heat sources were four paralleled contacts constructed by springs (Sn/CuSn-alloy) in socket and a plug sheet (Ni/Steel) while mating. The contact interfaces were detected by scanning electronic microscope (SEM) and X-ray energy dispersive spectros- copy (XEDS), obvious wear tracks and various contaminants, including element Si, Al, Na, K, S, Cl, O, etc., were found. The contamination degrees on the four paralleled contacts were different, so that the ratio of average contact resistance on the four contacts was about 5:8:3:1. The maximum contact resistance on contacts of the plug sheet reached 28 ?. The main failure rea- sons were fretting and contamination between the contact interfaces. Fretting simulation showed that connection resistance of connectors was raised up, even to ohms level. When the current increased to 5 A, the socket housing was heated and decom- posed. By the thermal analysis, it was estimated that the connector would be burned under the lower current if the current was not evenly distributed on the four paralleled contacts caused by uneven contamination. Improvement methods for connector failure are also discussed.

关键词： connector Thermal failure Fretting contamination

Thixocasting combination spanners using stainless steel X39CrMo17

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中国有色金属学会会刊：英文版 2010年第S3期20卷 998-1004页

作者： M.BüNCK E.SUBASIC A.BüHRIG-POLACZEK K.JIANG S.MüNSTERMANN J.M.SCHNEIDER K.FICKERT H.J.GüNTHER Foundry Institute at RWTH Aachen University AachenGermany Materials Chemistry at RWTH Aachen University AachenGermany HAZET-Hermann Zerver gmbh & co.kg RemscheidGermany PlaTeG gmbh SiegenGermany

Forging is state-of-the-art for producing hand tools on an industrial *** to high demands on the stiffness and the fracture toughness,high-strength forging steels were used to provide cavity-free components with high mechanical load ***,forging is a cost-effective mass production process but,in spite of all its advantages,it has its limitations,*** the freedom of ***,because of the extreme thermal loading(particularly with regard to permanent moulds) and the frequently unavoidable casting defects,hand tools are not *** means of thixocasting steel,technical difficulties can be reduced and new options are provided which allow the manufacturing of components with much higher complexity than that using *** near-net shape production,manufacturing steps and costs can be ***,steels,which are difficult to forge but nonetheless have high potential for specific applications(such as high strength or corrosion resistant steels),can also be *** cooperation with industrial partners,X39CrMo17 stainless steel combination spanners with 17 mm width across flats were *** dies were designed and optimized by simulation,the hot forming X38CrMoV5 tool steel as well as the molybdenum alloy TZM were selected as the tool *** dies were treated by a plasma nitriding process and subsequently coated with crystalline Al2O3 protective coatings by plasma-enhanced chemical vapor deposition(PECVD).During the experiments,combination spanners were successfully cast in the semi-solid *** parts were heat-treated to enhance the toughness of components,which was subsequently measured by a standardized torque ***,a hypothetical approach of a possible,industrial batch process was carried out using the simulation software MAGMAsoft.

关键词： thixocasting X39CrMo17 steel casting semi-solid MAGMAsoft simulation

Water-Lubricated Ni-Based composite(Ni-Al_2O_3,Ni-SiC and Ni-ZrO_2)Thin Film coatings for Industrial Applications

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Acta Metallurgica Sinica(English Letters) 2016年第1期29卷 8-16页

作者： Rizwan Sarwar Bajwa Zulfiqar Khan Vasilios Bakolas Wolfgang Braun Faculty of Science and Technology Sustainable Design Research CentreBournemouth University Talbot Campus Advanced Bearing Analysis Schaeffler Technologies GmbH& Co.KG

In this work, pure nickel and Ni-based nanocomposite coatings （Ni-AI2O3, Ni-SiC and Ni-ZrO2） were pro- duced on steel substrate by using pulse electrodeposition technique. The industrial performance tests were conducted to evaluate the wear resistance, corrosion resistance, adhesion strength and wettability behaviour of newly developed coat- ings. Rolling contact ball-on-disc tribometer was used to assess anti-wear behaviour of these coatings under water- lubricated contacts. The results showed that the wear- and corrosion resistance properties of nickel alumina and Ni-SiC composite coatings significantly improved than that of pure Ni and Ni-ZrO2 coatings. The adhesion and wettability results of Ni-A1203 composite showed better performance when compared to the rest of the coatings. The effects of incorporating nanoparticles on the surface microstructure, interface adhesion and distribution of the particles were also investigated. The coatings were characterized by using scanning electron microscopy, X-ray diffraction analysis and 3D white light inter- ferometry. The wear failure behaviour of these coatings was further examined by post-test surface observation under optical microscope.

关键词： Electrodeposition Wear-resistant corrosion-resistant Tribology Nanocoatings Water-lubrication

Selection for production-related traits in Pelargonium zonale: improved design and analysis make all the difference

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Horticulture Research 2017年第1期4卷 365-373页

作者： Heike Molenaar Martin Glawe Robert Boehm Hans-Peter Piepho Institute of Crop Science University of HohenheimBiostatistics UnitStuttgart70599Germany Klemm+Sohn gmbh&co.kg Stuttgart70378Germany

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental *** present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related *** required establishment of phenotyping protocols for root formation and stem cutting counts,with which 974 genotypes were assessed in a two-phase experimental *** present paper evaluates this *** possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic *** response to selection varied greatly,depending on the genotypic variances of the breeding population and traits.A varietal improvement of over 20%is possible for stem cutting count,root formation,branch count and flower *** contrast,indirect selection of stem cutting count by branch count or flower count was found to be *** established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of ***.

关键词： breeding traits branch

Efficient Noninvasive FHB Estimation using RGB Images from a Novel Multiyear,Multirater Dataset

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维普期刊数据库

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Plant Phenomics 2023年第3期5卷 533-545页

作者： DominikRößle LukasPrey LudwigRamgraber AnjaHanemann DanielCremers Patrick OleNoack TorstenSchön AImotion Bavaria Technische Hochschule IngolstadtIngolstadtGermany Hochschule Weihenstephan-Triesdorf WeidenbachGermany Saatzucht Josef Breun gmbh and co.kg HerzogenaurachGermany Technical University of Munich MunichGermany

Fusarium head blight(FHB)is one of the most prevalent wheat diseases,causing substantial yield losses and health *** phenotyping of FHB is crucial for accelerating resistance breeding,but currently used methods are time-consuming and *** present article suggests a noninvasive classification model for FHB severity estimation using red–green–blue(RGB)images,without requiring extensive *** model accepts images taken from consumer-grade,low-cost RGB cameras and classifies the FHB severity into 6 ordinal *** addition,we introduce a novel dataset consisting of around 3,000 images from 3 different years(2020,2021,and 2022)and 2 FHB severity assessments per image from independent *** used a pretrained EfficientNet(size b0),redesigned as a regression *** results demonstrate that the interrater reliability(cohen’s kappa,κ)is substantially lower than the achieved individual network-to-rater results,e.g.,0.68 and 0.76 for the data captured in 2020,*** model shows a generalization effect when trained with data from multiple years and tested on data from an independent ***,using the images from 2020 and 2021 for training and 2022 for testing,we improved the F_(1)^(w) score by 0.14,the accuracy by 0.11,κ by 0.12,and reduced the root mean squared error by 0.5 compared to the best network trained only on a single year’s *** proposed lightweight model and methods could be deployed on mobile devices to automatically and objectively assess FHB severity with images from low-cost RGB *** source code and the dataset are available at https://***/cvims/FHB_classification.

关键词： network consuming breeding