scholarly journals Investigations of the Friction Losses of Different Engine Concepts. Part 1: A Combined Approach for Applying Subassembly-Resolved Friction Loss Analysis on a Modern Passenger-Car Diesel Engine

Lubricants ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 39 ◽  
Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
David E. Sander ◽  
Theodor Sams
Keyword(s):  
Diesel Engine ◽  
Reduction Potential ◽  
Journal Bearing ◽  
Friction Reduction ◽  
Valve Train ◽  
Friction Loss ◽  
Loss Analysis ◽  
Piston Group ◽  
Timing Drive ◽  
Crankshaft Journal

This work presents the application of a combined approach to investigate the friction losses in a modern four-cylinder passenger-car diesel engine. The approach connects the results from engine friction measurements using the indication method and the results from journal-bearing simulations. The utilization of the method enables a subassembly-resolved friction loss analysis that yields the losses of the piston group, crankshaft journal bearings, and valve train (including the timing drive and crankshaft seals). The engine and engine subassembly friction losses are investigated over the full speed and load range, covering more than 120 engine operation points at different engine media supply temperatures ranging from 70 to 110 ∘ C. The subsequently decreasing lubricant viscosity due to higher engine media supply temperatures allow for the identification of friction reduction potentials as well as possible risks due to an onset of mixed lubrication. Furthermore, additional strip-tests have been conducted to determine the friction losses of the crankshaft radial lip seals, the timing drive, and the crankshaft journal bearings, thus enabling a verification of the calculated journal-bearing friction losses with measurement results. For the investigated diesel engine, a friction reduction potential of up to 21% could be determined when increasing the engine media supply temperature from 70 to 110 ∘ C, at engine speeds higher than n = 1500 rpm and part load operating conditions. At low engine speeds and high load operations, the friction loss reduction potential is considerably decreased and below 8%, indicating mixed lubrication regimes at the piston group and valve train.

scholarly journals Investigations of the Friction Losses of Different Engine Concepts: Part 3: Friction Reduction Potentials and Risk Assessment at the Sub-Assembly Level

Lubricants ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 39 ◽  
Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
David E. Sander ◽  
Theodor Sams
Keyword(s):  
Boundary Conditions ◽  
Journal Bearings ◽  
Friction Reduction ◽  
Valve Train ◽  
Specific Power ◽  
Passenger Cars ◽  
Reduction Potentials ◽  
Low Viscosity ◽  
Piston Group ◽  
Crankshaft Journal

One of the biggest requirements of today’s engine development process for passenger cars is the need to reduce fuel consumption. A very effective and economic approach is the use of low-viscosity lubricants. In this work, sub-assembly resolved friction reduction potentials and risks are presented for three different engine concepts. By using a developed combined approach, the friction losses of the base engines are separated to the sub-assemblies piston group, crankshaft journal bearings, and valve train over the full operation range of the engines. Unique analyzing of boundary conditions makes it possible for the first time to compare friction reduction potentials and possible risks, not only between diesel and gasoline engines for passenger car applications, but also with particular focus on the power density of the three engines. Firstly, the engines have been specifically chosen regarding their specific power output. Secondly, one identical SAE 5W30 lubricant suitable for all engines is used to neglect influences from different lubricant properties. Thirdly, identical test programs have been conducted at the same thermal boundary conditions at engine media supply temperatures of 70 ∘ C and 90 ∘ C. For the crankshaft journal bearings, high reduction potentials are identified, while risks arising occur at the valve train and the piston group systems.

scholarly journals A Comprehensive Numerical Study on Friction Reduction and Wear Resistance by Surface Coating on Cam/Tappet Pairs under Different Conditions

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 485
Author(s):  
Bugao Lyu ◽  
Xianghui Meng ◽  
Rui Zhang ◽  
Yi Cui
Keyword(s):  
Wear Resistance ◽  
Internal Combustion Engines ◽  
Numerical Study ◽  
Fuel Efficiency ◽  
Friction Reduction ◽  
Valve Train ◽  
Friction Loss ◽  
Contact Friction ◽  
Asperity Contact ◽  
Dlc Coatings

As a vital component in the valve train of internal combustion engines (ICEs), the cam/tappet pair undergoes high mechanical and thermal loads and usually works in a mixed and boundary lubrication regime. This leads to considerable friction loss and severe surface wear. Currently, the applications of diamond-like carbon (DLC) coatings for automotive components are becoming a promising strategy to reduce the friction and lower the wear. However, the practical performance of the coating is related to many factors, including friction coefficient, thermal properties, load conditions, and surface topography. In order to investigate these factors and successively improve the fuel efficiency and durability of the cam/tappet pair, a comprehensive multi-physics analytical model considering the mechanical, thermal and tribological properties of DLC coatings is established in this paper. Simulations are carried out for the coated as well as the uncoated cam/tappet conjunctions with different roughness at various ambient temperatures. The results show that both the fluid and asperity contact friction for the coated cam/tappet conjunction are significantly reduced due to their favourable characteristics. As a result, the friction loss of the coated cam/tappet pair is noticeably lower by almost 40% than that of the uncoated, despite a slightly higher asperity contact. In addition, the wear resistance of DLC coatings is also impressive, although the wear condition becomes progressively more severe with the increasing ambient temperature. Moreover, the roughness has complex effects on the friction and wear under different conditions.

scholarly journals Investigations of the Friction Losses of Different Engine Concepts. Part 2: Sub-Assembly Resolved Friction Loss Comparison of Three Engines

Lubricants ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 105 ◽  
Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
David E. Sander ◽  
Theodor Sams
Keyword(s):  
Friction Reduction ◽  
Valve Train ◽  
Friction Loss ◽  
Specific Power ◽  
Combined Approach ◽  
Tribological Behaviour ◽  
Engine Operation ◽  
Gasoline Engines ◽  
Lubrication Regimes ◽  
Wide Range

In this work, friction loss investigations and comparisons of three different four-cylinder engines for passenger car applications are presented, using a recently developed combined approach. By merging extensive experimental with reliable and predictive journal bearing simulation results, a sub-assembly-resolved friction loss analysis of the piston group, crankshaft journal bearings and valve train is conducted for all three engines. The engines have been chosen individually based on their specific power output and crank train geometry. The measurement program covers a wide range of corresponding engine operation points (identical speed, load and thermal boundary conditions). In addition, the investigations are carried out for different engine media supply temperatures ranging from 70 ∘ C to 110 ∘ C for a comprehensive consideration of the friction losses at reduced lubricant viscosity. For reasons of comparability, all investigations conducted in this work have been carried out using the same modern SAE 5W30 lubricant. This is done to exclude influences from different lubricant properties which may have significant effects on the tribological behaviour of the engines’ sub-assemblies. While the diesel engine showed a friction reduction potential over the entire engine operation range when increasing the engine media supply temperatures, the gasoline engines showed a different behaviour. For the gasoline engines, disadvantages arise especially at low engine speeds. By using the developed combined approach, it was possible to assign mixed lubrication regimes at the valve train systems and at the piston groups.

Diesel engine crankshaft journal bearings failures: Case study

2014 ◽  
Vol 44 ◽  
pp. 217-228 ◽  
Author(s):  
Aleksandar Vencl ◽  
Aleksandar Rac
Keyword(s):  
Diesel Engine ◽  
Journal Bearings ◽  
Crankshaft Journal ◽  
Engine Crankshaft

Study on Friction Reduction and Anti-Scuffing Technology of Duplex Ion Nitrocarburizing and Sulphurizing

2008 ◽  
Vol 373-374 ◽  
pp. 476-479 ◽  
Author(s):  
C.H. Hu ◽  
Shi Ning Ma ◽  
Yu Lin Qiao ◽  
J.P. Zou ◽  
Y.D. Gao ◽  
...  
Keyword(s):  
Surface Layer ◽  
Diesel Engine ◽  
New Technology ◽  
Friction Reduction ◽  
Bench Test ◽  
Wear Volume ◽  
Engine Cylinder ◽  
Nitrocarburized Layer ◽  
Alloy Cast Iron ◽  
Alloy Cast

A new technology, duplex ion nitrocarburizing and sulphurizing technology (DINS), for friction reduction and anti-scuffing applications of diesel engine cylinder was studied. Duplex ion nitrocarburized-sulphurized layer was prepared on the surface of CrMoCu alloy cast iron by using the DINS process. The morphology, phase structure and tribological behaviors under sulphur contained additive lubrication were investigated. Results show that the sulphide surface layer of the duplex layer is mainly composed of close-packed hexagonal structured FeS phase and cubic structured FeS2 phase. The nitrocarburized sub-surface layer of the duplex layer is mainly composed of Fe2C and Fe3N phases. The harder nitrocarburized layer can provide effective support to the softer sulphide layer and avoid its lamellar tear. The synergistic effect between the duplex layer and the sulphur contained additive lubricant, resulted in 10% and 33.3% reduction in coefficient of friction and wear volume, respectively, compared with those of the sulphurized surface, and 25% and 50.1% reduction, respectively, compared with those of the plain surface. Bench test of diesel engine further demonstrated that the DINS process can provide the treated cylinder with superior properties in anti-scuffing and friction reduction, so that it can be used to prolong the service life of the cylinder.

scholarly journals Методика для трибодиагностики судовых крейцкопфных дизелей на основе имитационного моделирования

2020 ◽  
Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko
Keyword(s):  
Diesel Engine ◽  
Simulation Model ◽  
Technical Condition ◽  
Operating Conditions ◽  
Marine Diesel Engine ◽  
Threshold Values ◽  
Piston Group ◽  
Marine Diesel ◽  
Cylinder Piston ◽  
Wear Products

Рассматриваются подходы по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующие переход объекта диагностирования судового крейцкопфного дизеля из одного технического состояния в другое. Показано, что существующие методики не учитывают индивидуальные особенности и техническое состояние деталей цилиндропоршневой группы. Предложено для решения задачи их трибодиагностики использовать разработанную имитационную модель, позволяющую провести моделирование процесса изнашивания цилиндровой втулки и поршневых колец судового дизеля и на основании полученных расчетов определить концентрацию продуктов износа поступивших в отработанное цилиндровое масло при различной скорости изнашивания трущихся деталей. Данные о фактической концентрации продуктов износа в отработанном цилиндровом масле в дальнейшем соотносятся с результатами моделирования, что позволяет оценить техническое состояние деталей цилиндропоршневой группы двигателя. Представлены результаты моделирования по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующее переход судового дизеля из исправного в несправное техническое состояние. Даны практические рекомендации по выбору пороговых значений содержания продуктов износа в отработанном цилиндровом масле для различных типов судовых крейцкопфных дизелей и условий их эксплуатации.The article examines approaches to determine the threshold values of the concentration of wear debris in used cylinder oil that characterize the transition of a ship crosshead diesel engine unit under test from one technical condition to another. It is shown that the existing methods do not take into account the individual characteristics and technical condition of the parts of the cylinder-piston group. To solve the problem of tribodiagnostics, it is proposed to use the developed simulation model, which allows modeling the wear process of the cylinder bushing and piston rings of a marine diesel engine and, based on the obtained results, determining the concentration of wear products issued in the used cylinder oil at different wear rates of the moving parts. The data on the actual concentration of wear products in the used cylinder oil are subsequently correlated with the simulation model results, which makes it possible to evaluate the technical condition of the parts of the engine cylinder-piston group. The article presents the results of modeling of threshold values determination of the concentration of wear products in used cylinder oil, that measure the transition of a marine diesel engine from a working condition to a malfunctioning technical condition. Practical recommendations are given on choosing threshold values for the concentration of wear products in used cylinder oil for various types of marine crosshead diesel engines and their operating conditions.

scholarly journals Friction Reduction Tested for a Downsized Diesel Engine with Low-Viscosity Lubricants Including a Novel Polyalkylene Glycol

Lubricants ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 9 ◽  
Author(s):  
David Sander ◽  
Christoph Knauder ◽  
Hannes Allmaier ◽  
Slavitsa Damjanović-Le Baleur ◽  
Philippe Mallet
Keyword(s):  
Diesel Engine ◽  
Friction Reduction ◽  
Low Viscosity ◽  
Polyalkylene Glycol

Multi-scale surface patterning – an approach to control friction and lubricant migration in lubricated systems

2019 ◽  
Vol 71 (8) ◽  
pp. 1007-1016 ◽  
Author(s):  
Philipp G. Grützmacher ◽  
Andreas Rosenkranz ◽  
Adam Szurdak ◽  
Markus Grüber ◽  
Carsten Gachot ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Journal Bearing ◽  
Friction Reduction ◽  
Patterned Surfaces ◽  
Test Rig ◽  
Content Type ◽  
Multi Scale ◽  
Surface Patterns ◽  
Lubricant Migration ◽  
Scale Surface

Purpose The paper aims to investigate the possibilities to control friction in lubricated systems by surface patterning, making use of a multi-scale approach. Surface patterns inside the tribological contact zone tend to directly reduce friction, whereas surface patterns located in the close proximity of the contact area can improve the tribological performance by avoiding lubricant starvation and migration. Finally, optimized surface patterns were identified by preliminary laboratory tests and transferred to a journal bearing, thus testing them under more realistic conditions. Design/methodology/approach Surface patterns on a large scale (depth > 10 µm) were fabricated by micro- and roller-coining, whereas surface patterns on a small scale (depth < 2 µm) were produced by direct laser interference patterning. The combination of both techniques resulted in multi-scale surface patterns. Tribologically beneficial surface patterns (verified in ball-on-disk laboratory tests) were transferred onto a journal bearing’s shaft and tested on a special test-rig. To characterize the lubricant spreading behavior, a new test-rig was designed, which allowed for the study of the lubricant’s motion on patterned surfaces under the influence of a precisely controlled temperature gradient. Findings All tested patterns accounted for a pronounced friction reduction and/or an increase in oil film lifetime. The results from the preliminary laboratory tests matched well, with results from the journal bearing test-rig, both tests showing a maximum friction reduction by a factor of 3-4. Numerical investigations, as well as experiments, have shown the possibility to actively guide lubricant over patterned surfaces. Smaller periodicities, as well as greater structural depths and widths, led to a more pronounced anisotropic spreading and/or greater spreading velocities. Multi-scale surfaces demonstrated the strongest effects regarding the lubricant’s spreading behavior. Originality/value Friction, as well as lubricant migration, can be successfully controlled by using micro-coined, laser-patterned and/or multi-scale surfaces. To the best of the authors’ knowledge, the study demonstrates for the first time the unique possibility to transfer results obtained in laboratory tests to a real machine component.

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