Miba Bearing Group

Laakirchen, Austria

Miba Bearing Group

Laakirchen, Austria
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News Article | May 26, 2017
Site: www.materialstoday.com

Peter Mitterbauer, the long-standing chairman of the board of management at Miba, has been named as an honorary doctor at the Vienna University of Technology for his contribution to Austrian innovation. The Miba Sinter Group has cooperated closely with the Vienna University of Technology for 40 years, during which time many joint research projects were successfully implemented, the company said. In addition, more than 20 dissertations and dissertations have been successfully completed on behalf of Miba. In its more than 30-year collaboration with the Institute of Solid-State Physics, Miba Bearing Group has researched the field of sputter technology for the bearing shells of truck and passenger car engines to the production stage. Peter Mitterbauer was the first chairman of the Austrian Research Promotion Agency (FFG) to reorganize Austrian research funding and strengthen Austria as a technology and innovation country in the international environment. This story is reprinted from material from Miba, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.

Aufischer R.,Miba Bearing Group | Walker R.,Miba Bearings U.S. LLC | Offenbecher M.,Miba Bearing Group | Feng O.,MPCC Bearings | Hager G.,Miba Bearing Group
ASME 2015 Internal Combustion Engine Division Fall Technical Conference, ICEF 2015 | Year: 2015

The development of combustion engines is heavily influenced by environmental regulations and efficiency. Since the environmental regulation have influenced engine design already with special combustion system and exhaust gas treatments, efficiency and the greenhouse gas CO2 has become a major issue for further development. CO2 emissions and fuel efficiency are linked and are directly influenced by the internal friction of the combustion engine. One major part of this internal friction is coming from the crank train bearings. Since we have to consider different operating conditions for the crank train bearings like hydrodynamic and mixed friction (hydrodynamic in combination with boundary contact), working principles as well as different engine operating conditions like full load, idle, start stop etc. different measures need to be employed for a friction reduced crank train. The optimal dimensioning of the bearings in combination with oil viscosity reduction are already known to a certain extent. Nevertheless they result in changes of bearing loads and may in consequence increase the share of boundary friction. Therefore, only looking on these two optimization steps is not enough. In addition the friction coefficient between bearing and shaft as well as the interaction between bearing surface and lubricant need to be addressed to reduce friction loss. In order to gain a complete picture, influences and the interaction of • geometric properties and bearing dimensions, • friction coefficient of bearings in combination with crankshaft materials, • oil formulation, viscosity and their interaction with engine application and duty cycle as well as • losses caused by the lubrication system design and components are investigated and analyzed based on simulation and testing. At first the different steps are investigated individually and secondly combinations and interactions are derived on basis of parameters derived on tribological tests and material data. Oil viscosity as major driver during hydrodynamic operation but also the influence of additive packages during mixed friction is roughly estimated on basis of tribological investigations. Since the overall friction system and its optimization are very complex, an example for a truck engine in different applications shows advantages and disadvantages of the different approaches. Also border lines given by operational risk and improvement limits are explained. The improvement options given by bearing materials and special coatings are explained in combination with different engines and engine applications. Further development activities, ways of collaboration between engine manufacturer and bearing supplier and an outlook on up-coming bearing system are completing the picture for a holistic approach on friction reduction in crank train bearings. Copyright © 2015 by ASME.

Aufischer R.,Miba Bearing Group | Walker R.,Miba Bearings U.S. LLC | Offenbecher M.,Miba Bearing Group | Hager G.,Miba Bearing Group
Journal of Engineering for Gas Turbines and Power | Year: 2014

Engine development, driven by environmental considerations outlined in the different emission regulations, fuel economy, and fuel availability in combination with economical boundary conditions, needs new approaches in bearing material and design. Since gas engines are gaining market share and firing pressures increase in diesel engines in order to fulfill fuel economy, a special focus has also been taken to tailor-made bearings for these applications. This complex task has to consider lining compound material strength and stability under different conditions like oil condition and dilution. Thin overlays with long-term wear resistance and mixed friction capabilities as well as robust design for extraordinary events like dirt shock loading or adaptations at the engine start are necessary. To fulfill all these requirements, different tasks have to be considered: (1) bearing lining and steel shell compound to fulfill assembly requirements to combine a safe bearing seat with antifretting and high strength with base tribological characteristics, (2) design and use of different layers to compensate weakness of the one layer with the strength of another layer, (3) incorporation of special running conditions and cost reduction approaches in the layer design like polymer coatings for start stop and shaft designs with rougher surface finishes, and (4) bearing design incorporating special shapes to cope better with deflections and geometric deficiencies of a special engine design or application In this publication, existing and new lining compound approaches, including lead-free designs, a variety of different overlays from electroplated, polymer and sputtered ones, are briefly described. Additionally, it is explained how these layers are combined and how they work together to improve bearing performance. Testing of the bearing components and designs on bearing test rigs with new test conditions considering dirt shock and misalignment and their confirmation by engine running experiences are given for a gas engine and a high speed diesel engine applications. A special outlook on how this approach can be extended to other applications for the sake of robustness, cost reduction, or performance increase will summarize the paper. Copyright © 2014 by ASME.

Pondicherry K.S.,Materials Center Leoben Forschung | Grun F.,University of Leoben | Godor I.,University of Leoben | Bertram R.,Infineum | Offenbecher M.,Miba Bearing Group
Lubrication Science | Year: 2013

This study compares two methods for model scale testing of ferrous/non-ferrous tribocouples under large area conformal contact condition, the kind existing in engine components such as journal bearings. Results show that the ring-on-disc method is better suited to visualise the performance of such tribosystems compared with the pin-on-plate method. The former offers greater sensitivity to minor changes in coefficient of friction and contact potential and is able to determine the thermal stability of the tribosystem under given conditions. Post-test surface characterisation revealed protective phosphorus-rich tribofilms on the surface of the steel counterparts from both test methods. Copyright © 2012 John Wiley & Sons, Ltd.

Grun F.,University of Leoben | Summer F.,University of Leoben | Pondicherry K.S.,Materials Center Leoben Forschung | Godor I.,University of Leoben | And 2 more authors.
Wear | Year: 2013

This paper describes the tribological functionality of hypereutectic AlSi under conformal contact conditions. Temperature and load bearing tests were performed with a ring-on-disc configuration with steel counterparts under fully formulated engine oil. Tribometric tests show significantly higher wear resistance and loadability of AlSi compared to pure Al. Post test surface characterization by light and electron microscopy revealed the load bearing functionality of the Si hard phases. Selective formation of protective tribofilms was observed exclusively on these Si particles and on the corresponding steel counterpart. This formation requires sufficient energy input and only takes place under harsh contact conditions. © 2012 Elsevier B.V.

Allmaier H.,Virtual Vehicle Competence Center | Priestner C.,Virtual Vehicle Competence Center | Six C.,Virtual Vehicle Competence Center | Priebsch H.H.,Virtual Vehicle Competence Center | And 2 more authors.
Tribology International | Year: 2011

It is the aim of this work to predict friction in journal bearings reliably and accurately under realistic dynamic working conditions. To this purpose elastohydrodynamic (EHD) calculations using an extensive oil-model and including an approach to the conformal roughnesses of the bearing surfaces are carried out for transient loads typical for current utility vehicles (40 MPa) as well as for considerably higher specific loads (70 MPa) and for different lubricants (SAE10, SAE20, SAE30 and SAE40) to account for a large span of working conditions ranging from full film lubrication to mixed lubrication with metalmetal contact. The results obtained from this simulation model are compared to measurements performed on a journal bearing test rig. We find that the results of the presented approach agree very closely with the experimental values. The presented approach allows consequently to investigate the effectiveness of changes in bearing geometry, bearing materials, bearing surface roughness, lubricant viscosity and engine operating conditions to reduce friction in journal bearings. © 2011 Elsevier Ltd. All rights reserved.

Grun F.,University of Leoben | Godor I.,University of Leoben | Javidi A.,University of Leoben | Pondicherry K.,Material Center Leoben | And 2 more authors.
Lubrication Science | Year: 2010

The layer-forming properties of different lubricants on technically used tribosystems were investigated. The experiments were carried out on a ring-on-disc test set-up on Fe/Fe- and Fe/Cu-based systems. Three different lubricants were used viz. base oil with detergents (Oil-A), oil with ZnP-based additives (Oil-B) and oil with P-based additives (Oil-C). We measured the electrical resistance between the rubbing surfaces. Surface characterisation (light microscopy, SEM/EDX and XPS) and tribometric results show differences in wear and friction properties. Oil-B showed profound layer formation on steel counterparts and correlation in the amount of Zn and S, P and O, respectively; whereas, none of the above was observed with Oil-A. Oil-C, however, showed thin but tribologically effective layer formation on ferrous system and a superior performance for the Fe/Cu system. © 2010 John Wiley & Sons, Ltd.

Priestner C.,Virtual Vehicle Competence Center | Allmaier H.,Virtual Vehicle Competence Center | Priebsch H.H.,Virtual Vehicle Competence Center | Forstner C.,MIBA Bearing Group
Tribology International | Year: 2012

Friction reduction is a fundamental factor in decreasing fuel consumption of internal combustion engines. During the design stage of the engine the simulation of friction in the crank mechanism plays a vital role to develop optimum solutions. Due to the interaction of oil and elastic structures with rough surfaces in slider bearings, complex simulation models have to be used for representing the relevant physical behavior. The following article is focused on crank shaft slider bearings of large engines. The article describes a procedure evaluated by measurements showing how to model wear profiles of slider bearings to reach a high quality friction forecast. A fundamental influencing factor of bearing friction is given by the mixed lubrication regime and it is considered in the simulation model as part of asperity contact friction and hydrodynamic friction. Further effects result from the compliance in radial and width directions of the bearing structure and the wear of the bearing surface. Furthermore, the specific operating conditions of the slider bearing such as load, temperature, shaft speed and oil characteristics are essential and have to be taken into account. The objective of this investigation is to propose the wear profile of the bearing surface for the simulation model to be treated iteratively, where simulation results for the amount of mixed lubrication are successively assessed. For this purpose an iterative procedure is introduced and validated by measurements on a slider bearing test rig. The applied simulation method is based on elastic multi-body systems; the lubrication film contact is calculated based on Reynolds differential equation via the pressure balance calculated iteratively in the time domain. The model accounting for the mixed lubrication regime is based on the theory of Greenwood and Tripp. © 2011 Elsevier Ltd.

Grun F.,University of Leoben | Godor I.,University of Leoben | Gartner W.,Miba Bearing Group | Eichlseder W.,University of Leoben
Tribology International | Year: 2011

This paper describes the analysis of overlay materials used in journal bearings. We conducted model tests using ring-on-disc test configuration and component tests on bearing test rigs. Appropriate test strategies were designed for investigating the running-in, stable operating, emergency running and break-down behaviour. We investigated three different types of overlays: PbSn18Cu2 galvanic, polymeric overlay (PAI matrix with MoS2-lamellae and graphite), PVD-coated AlSn20Cu-Sputter. Main results are: PbSn18Cu2 improves emergency running conditions. Polymeric overlay shows high need for running-in, where a particle structured surface is formed. AlSn20Cu-Sputter exhibits lowest wear and highest load capacity in component tests, but requires optimum running conditions. © 2010 Elsevier Ltd. All rights reserved.

Allmaier H.,Virtual Vehicle Competence Center | Priestner C.,Virtual Vehicle Competence Center | Reich F.M.,Virtual Vehicle Competence Center | Priebsch H.H.,Virtual Vehicle Competence Center | And 2 more authors.
Tribology International | Year: 2012

Within the framework of an attempt to predict friction in journal bearings reliably and accurately, the impact of neglecting the hydrodynamic pressure dependence of the lubricant in the oil-model employed in the simulation is investigated. To this task calculations are carried out with two different oil-models; namely, an extensive oil-model that includes the influence of the hydrodynamic pressure on the lubricant properties, as well as the still commonly used basic oil-model that neglects this dependence. To cover full film lubrication and mixed lubrication with significant metalmetal contact, two different lubricants (SAE40, SAE10) are studied. Calculations are conducted using a validated simulation model for dynamic loads with a maximum of up to 76 MPa that exceed typical main bearing loads found in current automotive ICEs. The results for both oil-models are compared to measurements performed on a journal bearing test rig. We find that the results obtained with both oil-models agree closely with the experimental values only for full film lubrication, while solely the extensive oil-model is able to give also reliable results for the case of mixed lubrication. © 2012 Elsevier Ltd. All rights reserved.

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