Wyniki wyszukiwania - BazTech

1

Wstępne badania diagnostyczne szybkoobrotowych silników o zapłonie samoczynnym na okręcie podwodnym z wykorzystaniem metody obwiedni drgań

Lus T.

Zeszyty Naukowe Akademii Marynarki Wojennej

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2013

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R. 54 nr 1 (192)

79--88

PL

W artykule zostały przedstawione wyniki wstępnych badań diagnostycznych okrętowych tłokowych silników spalinowych typu MB820 stosowanych na okrętach podwodnych (OP) Polskiej Marynarki Wojennej z wykorzystaniem nowej metody bazującej na kątowej analizie obwiedni przyspieszeń drgań. Silniki tego typu nie są wyposażone w zawory indykatorowe, zatem w celu oceny stanu technicznego układów cylindrowych można wykorzystać przebiegi drgań rejestrowane na głowicach cylindrów. W czasie badań czujniki ciśnienia wewnątrzcylindrowego były zamontowane na zaworach dekompresyjnych. Przebiegi ciśnienia były wykorzystywane jako sygnały referencyjne do synchronizacji przebiegów drgań. Wynikiem badań są tzw. dynamiczne fazy rozrządu, wykorzystywane przez specjalistów przy ocenie stanu technicznego i regulacji poszczególnych cylindrów silnika.

EN

Checking and tuning of the fuel injection valves opening pressures, fuel valves timing and exhaust or inlet valves clearances is a common practice in high-speed marine diesel engines maintenance. Cost lowering tendency in engine maintenance schedules and unmanned vessel’s propulsion plants need new approach to these old and reliable procedures. Dynamic valve gear timing diagrams are indispensable to perform an accurate engine tuning. A new original diagnostic and tuning method for high-speed marine diesel engine MB820 type is presented in the paper. In the principle this method based on measurements of: internal cylinder pressure curves and on vibration signals. Typical diagnostic methods which based on vibration signals analysis are sensitive to engine load and speed changes. Tests presented in this paper were focused on the possibilities and differences of the dynamic timing diagram assessing at engine rated load and when idling.

2

Diagnostics research of high-speed marine diesel engines using envelope vibration method

Lus T.

Silniki Spalinowe

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2011

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R. 50, nr 3

EN

Tests results of the new diagnostic method dedicated to marine high-speed diesel engines type MB820 fuel injection system and valve gear mechanism tuning are presented in the paper. These engines are not equipped with indicator valves so vibrations traces registered on the cylinder heads are used to assess the engine technical condition. The cylinder pressure sensors were connected to the decompression valves to get the reference signal for vibration traces, which is not a standard procedure on the MB820 engines. The results of the investigation are the dynamic timing parameters of the engine which could be used by specialists to compare engine internal processes and assess its technical condition.

PL

W referacie zostały przedstawione wyniki badań instalacji wtrysku paliwa i mechanizmu rozrządu szybkoobrotowych okrętowych tłokowych silników spalinowych typu MB820 z wykorzystaniem nowo opracowanej metody bazującej na kątowej analizie obwiedni przyspieszeń drgań. Silniki tego typu nie są wyposażone w zawory indykatorowe więc dla oceny stanu technicznego układów cylindrowych oraz procesu spalania próbuje się wykorzystać rejestrowane przebiegi drgań rejestrowane na głowicach cylindrów. Wynikiem badań są tzw. przebiegi czasowe a raczej przebiegi kątowe drgań, które są wykorzystywane przy ocenie stanu technicznego i regulacji poszczególnych cylindrów silników.

3

Tuning method for high-speed marine diesel engine MB820 Type

Lus T.

Journal of KONES

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2010

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Vol. 17, No. 2

277-284

EN

Checking and tuning of the fuel injection valves opening pressures, fuel valves timing and exhaust or inlet valves clearances is a common practice in high-speed marine diesel engines maintenance. Cost lowering tendency in engine maintenance schedules and unmanned vessel's propulsion plants need new approach to these old and reliable procedures. Conventional maintenance methods for engine valve gear mechanism depend on valve clearances checks between valve stem and rocker arm and valve timing diagram checks on crankshaft flywheel. But how to observe valves' timing diagram on working engine and what is the difference between static and dynamic valves timing diagram and in the end how engine load and speed changes disturb observed parameters? Answers for these and other questions for high-speed marine diesel engines MB820 type are given in this paper. Dynamic valve gear timing diagrams are indispensable to perform an accurate engine tuning. A new original diagnostic and tuning method for high-speed marine diesel engine MB820 is presented in the paper. In the principle this method based on measurements of: internal cylinder pressure curves and on vibration signals. Typical diagnostic methods which based on vibration signals analysis are sensitive to engine load and speed changes. Researches presented in this paper were focused on the possibilities and differences of the dynamic timing diagram assessing at engine rated load and when idling.

4

Marine diesel engine valve gear mechanism diagnostics problems

Lus T.

Journal of KONES

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2009

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Vol. 16, No. 4

287-292

EN

Marine diesel engines have changed their construction last years because of electronic control implementation in fuelling process. Electronic control implementation could be also important in valve gear mechanism which is main part of the engine gas es exchange system. In this paper problems connected with of valve gear mechanisms operation and diagnostics have been presented. the diagnostic methods and processes which could impact diagnostic process will be shown together with examples from test bed and real vessels. diagnostic methods which based on vibration signals analysis are sensitive on engine load and speed change. separate engine cylinder 's loads generale differences in so called "dynamic valve gear diagrams " which will be shown for some marine engine types. opening and closing of inlet and exhaust valves generale vibration signals in entire engine structure. There are some tools available in signal analysis which gives opportunity to trace changes in signal patterns in real time monitoring systems. special diagnostic method based on vibration signal analysis worked out in the polish naval academy, gives opportunity to change engine maintenance philosophy from scheduled planed maintenance system to condition based maintenance system without fear about real operating engine conditions.

5

Improvement of the internal combustion engine cam-tappet pair characteristics using numerical step-by-step cam design method

Vasilyev A., Bakhracheva J.

Journal of KONES

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2009

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Vol. 16, No. 1

517-522

EN

In this paper the numerical step-by-step method of cam profile design is presented. The results of its using for internal combustion engine valve gear are submitted. Its basis is a principle of step-by-step formation of the tappet movement law taking into account restrictions, which permit to refuse of before hand, accepted cam profile description. Thus instead of the analytical law of tappet movement the numerical representation is used, and the algorithm of positive and negative acceleration forming provides maximum cam efficiency, depending on the tappet displacement diagram completeness and connected to it valve timing. A longside with formation of the tappet movement law definition of the necessary data for manufacturing and the control of the corresponding cam profile using various kinematic schemes is stipulated. This method allows to profile of maximum efficiency cams in view of many restrictions on parameters, connected to valve gear serviceability and reliability: contact stress in cam-tappet pair, pressure angle, coverage factor of the valve springs effort, radius of cam profile curvature, oil film thickness in the cam-tappet pair and the restrictions on the higher order of derivative from the tappet displacement on the cam turn angle. Efficiency ofa considered method has been confirmed at profiling cams for lines of tractor and automobile engines.