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1
Content available Distribution of ring pressure over a worn cylinder liner surface
Serdecki W., Krzymień P.
Combustion Engines
|
2015
|
R. 54, nr 2
53--63
EN
A trial to define the effect of changes in cylinder geometry on compression ring pressure distribution has been presented in this paper which refers to the earlier papers of the authors. The analysis encompasses these cylinders where both circumferential and axial deformations occurred, relative to constructional and assembly errors but above all to engine operation. The conclusions withdrawn from these analyses were applied to exemplary calculations that try to evaluate the effect of cylinder deformation on correct collaboration of ring and liner and particularly on possibility of circumferential gaps leading to blow-by. The drafts presented in the paper show exemplary results of ring pressure distribution for a complete ring path between the dead centers and selected engine operational data. Moreover, such areas of cylinder surface were shown where slots between compression ring and cylinder liner might occur with high probability.
PL
W niniejszym opracowaniu, wiążącym się tematycznie z wcześniejszymi publikacjami autorów, dokonano próby określenia wpływu zmian geometrii cylindra na rozkład nacisku uszczelniającego pierścienia tłokowego. Analizami objęto cylindry, w których wystąpiły zarówno obwodowe, jak i osiowe zmiany kształtu, spowodowane np. błędami konstrukcyjnymi i montażowymi, ale przede wszystkim związane z eksploatacją silnika. Wynikające z tych analiz wnioski wykorzystano do przykładowych obliczeń, obejmujących ocenę wpływu deformacji cylindra na poprawność współpracy pierścienia z gładzią cylindra, a w szczególności na możliwość pojawienia się szczelin obwodowych, ułatwiających wystąpienie przedmuchów gazów. Na zamieszczonych w opracowaniu wykresach pokazano przykładowe wyniki obliczeń rozkładu nacisku pierścienia na gładź cylindra, obejmujące całą drogę pierścienia pomiędzy punktami zwrotnymi, dla wybranych parametrów pracy silnika spalinowego o ZS. Wskazano również obszary położone na gładzi cylindra, w których występuje duże prawdopodobieństwo pojawienia się szczelin pomiędzy gładzią cylindra a powierzchnią ślizgową pierścienia uszczelniającego.
2
Content available Analysis of parameters variability of compression ring and cylinder liner collaboration during engine operation
Serdecki W., Krzymień P.
Journal of Polish CIMAC
|
2014
|
Vol. 9, no 1
121--128
EN
Construction of piston-rings-liner assembly of contemporary engines of low and medium power secures a long time reliable operation. In the case of engines of higher output, e.g. marine and railway ones still occur failures caused by improper collaboration of piston rings and cylinder liner. One can mention variations in collaboration surface and difficulties with supply and proper distribution of lubricating oil over the entire surface of cylinder liner among the most important ones. Changes in value of parameters characteristic for compression ring and cylinder liner collaboration that occur during engine run have been analyzed in the following study. Attention has been paid to the ability of ring contact with the liner, especially those features that cause the formation of light slots between ring face and liner surface. Drafts presented in the paper show the results of compression ring pressure distribution and the geometry of light slots carried out for technical data of the earth moving machine engine. Simulation computations take into account both the effect of engine operation cycle phase and selected stages of its run as well.
3
Content available Variability of compression ring pressure against the deformed cylinder wall during engine operation
Serdecki W.
Journal of Polish CIMAC
|
2013
|
Vol. 8, no 1
73--79
EN
Problems connected with the circumferential distribution of compression ring pressure against the deformed cylinder wall during engine run were presented in this paper. In particular, division of the resultant force pressing the ring against the wall into component connected with ring own elasticity and the one originated from gas pressure was carried out and the influence of each force at individual phases of engine run was evaluated as well. The relationship allowing calculation of the circumferential ring pressure was also established. The paper contains figures and drafts obtained in a course of exemplary calculations of compression ring pressure concerning a running bulldozer engine. These figures show the areas of cylinder wall where so called light slots can appear. Conclusions resulting from the carried out simulation tests are discussed in Summary. The need for further investigations mentioned in presented study was shown as well.
4
Content available An analysis of phenomena accompanying ring collaboration with worn cylinder surface
Serdecki W., Krzymień P.
Combustion Engines
|
2013
|
R. 52, nr 2
40--47
EN
The presented study which refers to the earlier papers of the authors discusses an effect of cylinder wall deformation on the effectiveness of compression ring operation. Presented models permit a mathematical description of a deformed cylinder and definition of ring wall pressure relative to these deformations. The drafts presented in the paper, obtained in a course of calculations of a compression ring installed in a work machine engine, allow to evaluate the effect of cylinder deformations on distribution of ring circumferential pressure and point out areas where the light slots could occur.
PL
W niniejszej pracy, wiążącej się tematycznie z wcześniejszymi publikacjami autorów, określono wpływ zmian kształtu otworu cylindra na skuteczność pracy pierścienia uszczelniającego. Zaprezentowano modele, umożliwiające matematyczny opis odkształconego otworu cylindra, a także wyznaczenie odpowiadającego tym odkształceniom nacisku pierścienia na gładź cylindra. Na zamieszczonych w opracowaniu wykresach, uzyskanych podczas obliczeń pierścienia uszczelniającego pracującego w silniku spalinowym maszyny roboczej, pokazano przebiegi pozwalające ocenić wpływu wartości zniekształcenia otworu cylindra na rozkład nacisków obwodowych, a także wskazano miejsca, w których możliwe jest pojawienie się tzw. szczelin świetlnych.
5
Content available Analysis of ring pressure distribution on a deformed cylinder face
Serdecki W.
Journal of Polish CIMAC
|
2012
|
Vol. 7, no 1
219-226
EN
Elastic properties of correctly designed piston compression ring should provide full contact of ring face and the cylinder surface. Actually, because of various phenomena and processes experienced during engine assembly and operation an initially cylindrical liner is being subjected to wear and deformations which eventually affects that contact and cause formation of slots distributed along the cylinder circumference. Following paper describes the most often met deformations of cylinder and presents an evaluation of their influence on the process of compression ring collaboration with the surface of misshaped cylinder. Mathematical relations that allow to calculate the change of ring cylinder pressure and location of areas where blow-by can occur have been presented as well. The presented analyses were supplemented with charts illustrating changeability of certain quantities characteristic for ring and liner construction, using a marine engine ring as an example. The relations established during investigation will be used for a construction of mathematical model of phenomena accompanying the operation of piston-cylinder assembly elements, in the subject of blow-by in particular.
6
Content available How the wear of cylinder liner affects the cooperation of piston - cylinder assembly of IC engine
Serdecki W., Krzymień P.
Journal of KONES
|
2012
|
Vol. 19, No. 1
357-363
EN
A ring pack of modern IC engine consists of at least one compression ring that should guarantee secure a necessary tightness of combustion chamber. A circumferential wall pressure of correctly designed compression ring should be sufficient to achieve a full contact between wall and ring, which means light tightness preventing gas blowby. Lack of tightness is being considered as a principal cause of deterioration of engine performance data including torque instability, and a rapid grow in ring and cylinder wear within the area of blow-by. During engine design process mathematical models are applied which implement analytical and numerical methods of calculation. Analytical methods that were used earlier presented a limited range of application and lower accuracy in comparison to the numerical methods but they allowed achieving approximate results quicker. Taking this into consideration the presented study describes the most important relations between ring geometry and its wall pressure, which were obtained using the analytical methods. Presented formulas facilitate the evaluation of cylinder wear effect on the ring circumferential pressure distribution, especially the change in liner diameter. An attempt of light slits evaluation has been performed as well. The study was supplemented with graphs and calculative example.
7
Content available remote The effect of changes in cylinder liner geometry on the operation of piston compression ring
Serdecki W., Krzymień P.
Czasopismo Techniczne. Mechanika
|
2012
|
R. 109, z. 3-M
285--294
EN
Presented paper deals with cylinder deformations which could be most often encountered and tries to explain the causes of such situations. The essential part of the paper presents relations which allow to describe cylinder shape of any geometry and the attached example explains better the principles of their application. The obtained relations will be applied to the constructed mathematical model, in particular in a module describing the link between cylinder deformations and blowby during engine run. It should be added that the presented study is a part of a series concerning the collaboration of compression ring with the cylinder wall observed on a running engine.
PL
W niniejszym opracowaniu opisano najczęściej spotykane deformacje cylindra i dokonano próby wyjaśnienia przyczyn ich powstawania. W zasadniczej jego części zaprezentowano związki pozwalające opisać kształt cylindra o dowolnej, złożonej geometrii, a załączony przykład obliczeniowy pozwala lepiej wyjaśnić zasady ich stosowania. U zyskane zależności zostaną wykorzystane w budowanym modelu matematycznym, w module dotyczącym wpływu odkształceń cylindra na przedmuchy gazów spalinowych w czasie pracy silnika. N ależy dodać, że niniejsze opracowanie jest częścią większego cyklu dotyczącego współpracy uszczelniającego pierścienia tłokowego z gładzią cylindra w czasie pracy silnika spalinowego.
8
Content available Distribution of piston compression ring pressure against the deformed cylinder wall
Serdecki W., Krzymień P.
Silniki Spalinowe
|
2011
|
R. 50, nr 2
17-24
EN
The following study presents typical cylinder deformations that come up during engine assembly and operation and provides results of analysis of how these changes affect the operation of the compression ring. Special attention has been paid to the effect of cylinder diameter increase on the distribution of the circumferential wall pressure and the cause of light gaps formation has been explained. The analyses presented in the following paper have been carried out using a computer program that has been formulated based on a compression ring mathematical model. Exemplary results of simulation have been obtained for a medium speed generator engine of a cylinder diameter of 0.48 m.
PL
W opracowaniu opisano typowe deformacje cylindra pojawiające się podczas montażu i eksploatacji silnika oraz przedstawiono wyniki analizy wpływu tych zmian na pracę pierścienia uszczelniającego. W szczególności omówiono wpływ wzrostu średnicy cylindra na rozkład obwodowego nacisku pierścienia oraz wyjaśniono przyczyny powstawania tzw. szczelin świetlnych. Prezentowane w opracowaniu analizy przeprowadzono przy wykorzystaniu programu obliczeniowego powstałego na podstawie modelu matematycznego uszczelniającego pierścienia tłokowego. Zaprezentowane w artykule przykładowe wyniki symulacji uzyskano dla agregatowego silnika średnioobrotowego o średnicy cylindra równej 0,48 mm.
9
Content available Analysis of relations between the compression ring characteristic parameters
Serdecki W.
Journal of Polish CIMAC
|
2011
|
Vol. 6, no 2
171-180
EN
A proper design of compression ring secures its correct and long term operation. A good ring contact to cylinder wall along the whole circumference with the required distribution of circumferential pressure at the same time are symptoms of this correctness. The analytical methods and more often numerical ones are applied when designing piston rings. A characteristic parameter most often designated as K, which facilitates the comparison of different ring designs and allows for anticipation of its elastic properties is used at the stage of ring design. The following study presents the most significant mathematical relations between the ring geometry and forces that are acting on ring, and shows that results of force operation could differ relative to the point of their application. Relations between the tangential force and the circumferential one have been established as well. For three compression rings verifying tests consisting in definition of selected parameters using analytical and numerical methods have been carried out. The analysis of attained results and trials on explanation of noticed discrepancies are presented in the study as well.
10
Content available Dependence of piston ring parameters determination accuracy on the method of calculation
Serdecki W., Krzymień P.
Journal of KONES
|
2011
|
Vol. 18, No. 4
435-441
EN
Mathematical models are commonly used at the stage of piston ring design and during examination of ring collaboration with liner surface. Both analytical and numerical methods are used for development of such models. In the case of models based on analytical methods the range of their application is usually limited only to selected cases while the use of numerical methods allow to widen the range of their applications but their accuracy depends on increment used. The paper presents a procedure of verification of the piston ring mathematical model constructed by the authors using numerical methods. Conformity between the results obtained using this program and the results of analytical calculations concerning the displacement of ring free ends brought about by the acting loads was the aim of the analysis. Exemplary computations were carried out for three compression rings of different geometry. Regarding the conformity of achieved results as satisfactory for practical use probable causes of observed discrepancies were pointed out. Relations between energy accumulated in curved bar and loading force (according to the Castiliano's theorem) were used in a course of calculations. Exemplary calculations were carried out for compression rings of three types engine, i.e. automotive, bulldozer and marine ones. A probable cause of differences between results of calculations carried out according to various analytical methods have been pointed out assuming their accuracy as satisfactory for practical purposes.
11
Content available Determination of compression ring wall pressure distribution
Serdecki W.
Journal of Polish CIMAC
|
2010
|
Vol. 5, no 1
171-178
EN
On a correctly designed engine piston-cylinder assembly the contact of ring and bore should take place through a layer of oil, called oil film. In order to obtain a continuous oil film a proper lubricating oil should be introduced into the region of node elements collaboration, sliding surfaces should have adequate geometry and parameters of collaboration should be chosen suitably. The ring pressure against the liner is one of important quantities that affect formation of oil film. Selection of ring pressure circumferential distribution is pretty complex and depends on a number of factors and changes along the engine life. Presented paper discuss the methods of ring pressure distribution along its circumference and indicate problems connected with measurements. Moreover, basic assumptions used for construction of compression ring mathematical model as well as results obtained using that model were presented for full and partial loads. A need for the construction of computational program that could take into consideration evenly worn and distorted bore surface have been validated as well.
12
Content available Compression rings of low-speed high power engines
Serdecki W., Krzymień P.
Journal of KONES
|
2010
|
Vol. 17, No. 4
415-422
EN
The paper describes the design of compression rings used in low-speed, high power marine engines and it analyses relations between the most important operational parameters. Ring material, dimensions, geometry of sliding surfaces, distribution of circumferential pressure as well as operational conditions (thermal and mechanical loads, way of lubrication) were taken into consideration for the analysis mentioned above. Moreover, the paper points at modifications in ring geometry that have been happening for last years, comparing previous and recent designs. The effect of ring circumferential pressure against liner on the piston-cylinder assembly operation has been considered and the causes of its variability have been pointed out as well. When presenting the methods of measurement and tangential force calculations basic advantages and disadvantages have been presented as well as the evaluation of changes resulting from the ring circumferential wear. The compression ring mathematical model developed by the authors allows for a precise definition of relations between ring geometry and distribution of ring circumferential pressure. A need for a more accurate method of ring circumferential pressure evaluation has been justified in summary, giving hints necessaryfor its preparation.
13
Content available remote Tests on piston ring – cylinder liner collaboration of high power engine
Serdecki W., Krzymień P., Brzeziński Ł.
Silniki Spalinowe
|
2009
|
R. 48, SC1
35--42
EN
Presented paper describes the most important modifications recently introduced to the high power engine piston-cylinder assembly and an analysis of effect of these changes on collaboration between rings and cylinder liner. One of the key issues brought about in the paper is the evaluation of constructional modifications performed on piston-cylinder assembly elements and their effect on oil film quality and friction losses encountered during operation of this assembly. Results of simulation tests on oil film formation on marine engine cylinder liner surface will be used for the analysis.
PL
W pracy opisano najważniejsze zmiany wprowadzone w ostatnich latach w budowie układu tłokowocylindrowego silników dużej mocy oraz przeanalizowano wpływ tych zmian na przebieg współpracy pierścieni z gładzią cylindra. Jednym z ważniejszych zagadnień poruszanych w pracy jest ocena wpływu zmian konstrukcyjnych elementów układu tłokowo-cylindrowego na jakości filmu olejowego tworzonego na gładzi cylindra oraz na straty tarcia towarzyszące pracy tego układu. Wnioski wynikające z dokonanego przeglądu zostaną wykorzystane przy budowie modeli matematycznych dotyczących kształtowania się parametrów filmu olejowego na gładzi cylindrowej silnika dużej mocy.
14
Content available Model Tests Of Piston Ring-Cylinder Liner Collaboration On High Power Engines
Serdecki W., Krzymień P.
Journal of Polish CIMAC
|
2009
|
Vol. 4, no 2
259-266
EN
Proper selection of materials for cylinder liner and piston rings, correct design of collaborating surfaces as well as the use of lubricating oils of better and better properties assure long and reliable operation of piston rings in small and medium size engines. In the case of high power engines, especially marine ones failures caused by incorrect collaboration of rings and liner still happen. Supply and correct distribution of lubricating oil over cylinder surface could be one of the causes of this phenomenon. Regulations introduced by classification societies make impossible research on piston ring – cylinder liner set of running engines. Mathematical models or simulation test benches are the possible way of carrying out such tests. This paper presents some test rigs and analytical models revealing their advantages and shortcomings.
15
Content available Model investigation of piston ring-cylinder liner collaboration on a high power engine
Serdecki W., Krzymień P.
Journal of KONES
|
2009
|
Vol. 16, No. 4
407-413
EN
Failures caused by improper collaboration between piston ring and cylinder liner still happen on engines ofhigh output, marine ones in particular. Among causes of this phenomenon one can mention higher mechanical and thermal loads of crank mechanism as well as difficulties in supply and distribution of lubricating oil over the entire surface of cylinder liner. It would be extremely difficult and because of regulations in most cases impossible to perform tests on correct collaboration between rings and liner of real running engine and on the other hand such tests on a test stand would be quite expensive. Use of mathematical models and tests on simulation model stands offers a way to reduce these costs. Basic dependences connecting piston ring geometry with oil film parameters and introductory results of computations performed with the use of analytical model of test stand will be presented in this paper. The tests are to be carried out for ring geometry corresponding to that of marine engine rings. Due to that, using presented earlier formulas and computer program constructed by the authors the phenomena accompanying operation of different versions of rings were analyzed from the point of oil film thickness and generated friction losses. These ring versions which revealed the most advantageous properties will be made and tested on a test stand.
16
Content available Determination Of Cranktrain Frictional Resistance Using The Motored Engine Method
Serdecki W., Krzymień P.
Journal of Polish CIMAC
|
2008
|
Vol. 3, no 2
9-13
EN
Friction losses generated in engine kinematic nodes have an essential effect on its general efficiency. Measurement of these losses and indication of areas where they are generated can contribute to their minimization at the stage of engine design and during its operation as well. Most of the loss measurement methods requires an intervention in engine construction. The method of engine motoring does not require such intervention and at the same time offers possibility of precise measurement of engine resistance. The results obtained with the use of this method are considered hardly precise (among others because of different conditions during engine normal operation and its motoring), nevertheless they allow to estimate the influence of various effects on resistance observed on an engine. This study presents the results of tests on the effect of certain quantities characteristic for engine operation as well as properties of lube oil applied on the course of instantaneous values of motored engine torque. Another achievement of the study is the recommendation of test conditions securing highest possible accuracy of engine resistance torque determination. The simulation tests were carried out on the 170A.000 engine.
17
Content available Assessment of possibilities of testing the high power engine piston ring-cylinder liner collaboration on a model test stand
Serdecki W., Krzymień P.
Journal of KONES
|
2008
|
Vol. 15, No. 2
441-448
EN
The design of piston rings for modern engines of low and medium power guarantees long reliable operation, thanks to proper selection of materials, suitable geometry of mating surfaces as well as the use of lubricating oils of appropriate quality. At present, the efforts of constructors focus on other aspects of operation of this kinematic pair. The aim is to reduce costs of engine run as well as improvement of ecologic indices (eg. by the reduction in lube oil consumption, reduction of friction losses through the reduction in ring number, and so on). There still occur failures caused by incorrect collaboration of piston rings and cylinder liners on engines of high output, especially the marine ones. Higher mechanical and thermal loads of crank mechanism elements as well as difficulties with supply and correct distribution of lubricating oil over the liner entire surface are among the causes of these phenomena. Because of limited measurement possibilities the research on correct collaboration of piston ring and cylinder liner could be quite difficult and expensive on a real marine engine. Such research could be carried out far easier on a model simulation test rig. The presented paper will deal with the question if the test rig purposed for the investigation of kinematic pair collaboration - property of the Combustion Engine Chair - is suitable for evaluation of collaboration of marine engine piston ring with cylinder liner in the presence of lubricating oil.
18
Content available remote Analiza zmienności momentu oporowego silnika spalinowego małej mocy
Serdecki W.
Czasopismo Techniczne. Mechanika
|
2008
|
R. 105, z. 7-M
139-150
PL
Przebieg momentu obrotowego przekazywanego z silnika spalinowego do odbiornika mocy jest efektem działania różnego rodzaju sił, w tym przede wszystkim sił gazowych, tarcia i bezwładności. Analiza przebiegu poszczególnych sił wykazuje jednak, że wartość siły gazowej działającej podczas pracy silnika jest znacznie większa od pozostałych, co w efekcie utrudnia pomiar i analizę pozostałych sił. Problem ten można ograniczyć, prowadząc badania przebiegu siły tarcia w sytuacji, gdy siła gazowa nie występuje. W artykule przedstawiono analizę wzajemnych relacji, jakie zachodzą w układzie korbowotłokowym pomiędzy siłą tarcia i siłą bezwładności (oraz odpowiadającymi im momentami oporowymi) podczas badania silnika małej mocy metodą obcego napędu. W artykule przedstawiono również wyniki badań, związanych z wyznaczaniem związku łączącego lepkość dynamiczną oleju z temperaturą dla grupy olejów rodziny Elf.
EN
The course of torque transmitted from engine to power receiver results from various types of forces, including first of all the gas, friction and inertia forces. However, the analysis of individual force course shows that the gas force is far higher than the others, which makes the measurement and analysis of those forces difficult. This problem could be reduced when the friction force investigation is being carried out at the gas force absence. Following study presents the analysis of mutual relations between friction and inertia forces (and relative torques) in cranktrain when low power engine is motored. The paper presents also the relation between oil dynamic viscosity and temperature analyzed for the Elf lubricating oils.
19
Content available remote Analysis of possibilities of friction losses determination in engine crank mechanism
Serdecki W., Krzymień P., Brzeziński Ł.
Silniki Spalinowe
|
2007
|
R. 46, nr SC1
116-123
EN
Friction losses generated in kinematic nodes of IC engine, especially those in piston-cylinder assembly, affect the engine total efficiency to the considerable degree. Analytical determination of those losses using mathematical models of engine selected kinematic nodes requires verification carried out on real objects. These can be material models of these objects or engines appropriately arranged for measurements alike. This paper presents methods of determination of losses generated at some kinematic nodes of engine as well as ways of result verification.
20
Content available The Measurement Of Losses Generated In Kinematic Nodes Of Engine Run At Test Stand
Serdecki W., Krzymień P.
Journal of Polish CIMAC
|
2007
|
Vol. 2, no 1
469-476
EN
Reduction in losses accompanying the operation of IC engine requires previous identification of their sources and estimation of their value. Reduction in friction losses that is the most important component of the resistance to motion is particularly substantial. In following study the authors presented the best known methods of friction losses estimation pointing out their advantages and shortcomings. In authors’ opinion the method of balance of torques generated during engine run is the most accurate one. The basic source of error in this method is an additional torque due to the torsional vibrations. Finally, torsional vibrations calculations concerning the VWR5 TDI diesel have been presented as an example.
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