The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

ThyssenKrupp Metalúrgica Campo Limpo Ltda.
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Importance of Connecting Rod and Crankshaft Roughness Accuracy on Sliding Bearing Performance

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Larissa Galera, Alex de Souza Rodrigues
Digital Metrology Solutions, Inc.-Mark C. Malburg
Published 2015-09-22 by SAE International in United States
In recent years, the concern about pollutants emissions has increased along with as customer requirements for more efficient internal combustion engine (ICE). To satisfy these demands, new technologies have been introduced in ICE, such as smaller engine bearings, a reduction in the number of cylinders, variable displacements, peak cylinder pressure (PCP) increases, among other things. Sliding bearings are responsible for vital function under engine operation and also friction losses, impacting on fuel consumption as well as pollutants emissions. To maximize the bearing’s performance, it is important to guarantee a hydrodynamic regime, in order to reduce wear and avoid power loss due to metal-to-metal friction, and consequently, premature failure of engine components. Material roughness indicates, with oil film, the lubrication regime as boundary, mixed or hydrodynamic. Thus, it is important to characterize sliding bearings based on roughness in order to achieve tribological performance optimization, which ultimately impacts fuel consumption. Based on the above, this work shows different ways to characterize the bearing roughness for simulation, and the influence of this parameter on bearing performance.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Optimization of Lemon Shape Big End Profile Connecting Rod under Engine Operation in Elastohydrodynamic Regime

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Larissa Galera, Alex de Souza Rodrigues
Published 2014-09-30 by SAE International in United States
Nowadays, due to the emissions regulations and customer requirements for more economic vehicles there is a demand of more efficient Internal Combustion Engine (ICE). The hydrodynamic bearings play an important rule converting the piston reciprocating displacement into a rotational motion. Thus, considering the sliding bearings vital to define the engine life and also responsible for part of friction loss inside the engine, it is important to optimize its profile and consequently tribological performance parameters which impact on fuel consumption. All in all, this work shows the analysis between lemon shape big end bearing and cylindrical one, in order to evaluate the advantages and disadvantages related to this micro profile.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Usage of Multi-Disciplinary Genetic Optimization Algorithm in the U-Shape Crankshaft Structural Profile

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Wiliam Tean Su
Published 2014-09-30 by SAE International in United States
Nowadays, the market trends on engine components development are focused in lower emissions, fuel consumption reduction, downsizing and higher peak combustion pressure. In this scenario, macro-profile bearing optimization plays an important rule on stresses reduction and consequently structural safety factor increasing. Thus, a structural optimization was performed to define the best crankpin profile for a given crankshaft (named U-Shape crankpin profile). This profile can be designed with emphasis on mass and friction reduction without penalties on structural and torsional stiffness results. Since there is more than one objective, it is necessary to perform a multi objective optimization that will result in a Paretto frontier, in which all design points meet the targets. All in all, target of this work is to study the optimization step considered to define the U-Shape profile for a given crankshaft, especially the genetic algorithm (NSGA-II) as well as the benefits of the optimized macro-profile.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Multiphysics Simulation of Quenching Process of a SAE 1080 Steel Cylinder, Coupling Electromagnetic, Thermal and Microstructural Analysis

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Wiliam Su, Alex Rodrigues
State University of Campinas-Pedro de Paula, Renato Pavanello
Published 2014-09-30 by SAE International in United States
Mechanical components, such as parts of internal combustion engine, subject to cyclic loads can be submitted to quenching process in order to improve mechanical properties preventing fatigue failures in service. It is important that such components, due to quenching process, get a high hardness surface layer, increasing the resistance to fatigue, and a tenacious core, with a high capacity of absorbing impacts.In this paper, a multiphysics simulation method of quenching process using Finite Element Method is presented. The proposed simulation method include two stages: heating and cooling. In the first stage, the mechanical component, initially at ambient temperature, is heated by electromagnetic induction to a temperature above the steel austenitization. In the second one, the component is cooled by liquid immersion. The resulting microstructure is calculated using the Johnson-Mehl-Avrami-Kolmogorov model and Sheil's additive rule for diffusional transformation, while austenite-martensite transformation is calculated by Koistinen-Marburguer equation.The proposed method takes into account the variation of the material thermal properties as a function of temperature and microstructure, while the material electromagnetic properties are a function of temperature and…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental and Numerical Modal Analysis of 6 Cylinders Diesel Crankshaft

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Alex Rodrigues, Rafael Lima e Silva, Robson Cruz
Universidade Estadual de Campinas-Milton Dias Júnior, Sergio Villalva
Published 2011-10-04 by SAE International in United States
The crankshaft dynamic behavior of internal combustion engines are deeply influenced by its geometry and modal parameters. The modal density of a 6 cylinder crankshaft is high and, therefore, it is necessary the evaluation of its several modal parameters during the crankshaft development. This paper presents the calculation of modal parameters such as: natural frequencies, modal shapes and damping factors; of a 6 cylinder in line crankshaft from a Diesel engine. Two approaches are conducted, firstly, a numeric calculation based on finite element method to collect the free body shape modes and its natural frequencies, respectively. Successively, an experiment is realized by the use of an electro-dynamic shaker to excite the structure, and accelerometers to measure the acceleration in 21 interest points of crankshaft geometry. The 3 directions FRFs are presented for each point, and also, the estimation of modal parameters obtained by tools like CMIF, Stabilization Diagram and Polymax. Gathering the results, it is possible to correlate experimental and numerical shape modes and natural frequencies, and at last, the estimated damping factors are used…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Numerical Approach to the Thermal Effect on the Equivalent Dynamic Coefficients of Radial Bearings

ThyssenKrupp Metalúrgica Campo Limpo Ltda.-Diogo Stuani Alves
University of Campinas - UNICAMP-Katia Lucchesi Cavalca
Published 2011-10-04 by SAE International in United States
To analyze a complete real machine, it can be convenient to divide the system into sub-systems, analyzing each sub-system individually, and then, assembling them together in the whole system. Many of these sub-systems can be found in an automotive engine, being the hydrodynamic bearing one of the most common mechanical components present in all kinds of power generation systems. Journal bearings are linking elements between parts with relative motion, and these linking elements must work to support radial loads with minimal friction and power loss. In 1925, Stodola realized that the bearing is not a rigid support, but it works like a set of springs and dashpots whose characteristics have an expressive effect on the dynamical behavior of the supported rotating shaft. Consequently, to represent the bearings by equivalent coefficients of stiffness and damping became the basis of the journal bearings study, since those coefficients can easily be inserted in a finite element model of rotating systems supported by rigid or flexible structures. However, the most general analyses for bearings in the automotive industry are…
Annotation ability available