Wyniki wyszukiwania - Biblioteka Nauki

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Out-of-round tram wheels – current state and measurements

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Staśkiewicz T. , Firlik B.

Archives of Transport

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2018

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tom Vol. 45, iss. 1

93--103

EN

Railway or tram wheel is never perfectly round and its surface is not ideally smooth, even at the very moment after manufacturing. This induces dynamic interaction between wheel and rail while rolling, which may result in accelerated wear, fatigue cracking, corrugation formation (both on wheels and rails) and intensified vibroacoustic emission. This paper is an attempt of summarising the current scientific achievements concerning out-of-round (OOR) tram wheels. The gathered research may provide an introduction to the broader analysis of this issue in tram technology. However there is still very little scientific works dedicated directly to light rail vehicles such as trams. The measuring methodology of out-of-round tram wheels is also described in this article. Appropriate measurements were made on the wheels of selected vehicles operated by municipal tram company in Poznań. The obtained results allowed to learn the characteristic forms of out-of-round tram wheels, among which, several forms of polygonization (ovalization, triangularization, etc.) were observed. Therefore we confirmed the thesis, that the method of fixing tram wheel rims in the lathe has a significant effect on formation of the unevenness of its rolling surface, both when new (just after turning) and, after some mileage of use, when even small irregularities become amplified. We observed also that the amplitude values from 5th up to 10th harmonic orders were increased during the operation. The initial out-of-round shape of the wheel should be likely present on the worn wheel, but with increased amplitudes of irregularities. Wheel out-of-roundness should be identified and removed at the soonest possible state to prevent its development and generating issues in the future operation, that are for example: rolling stock and infrastructure damage, impaired comfort of passengers and city inhabitants. It makes out-of-round wheels a serious problem to cope with for the vehicle operators, which can lead even to a catastrophe.

2

Vibroacoustic comfort measurements on electric multiple unit driver’s stand during regular service

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Staśkiewicz T. , Kominowski J.

Journal of Mechanical and Transport Engineering

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2015

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tom Vol. 67, No. 3

41--52

EN

Due to the development of railway market in Poland, the amount of new traction units put into service is growing every year. The vehicles are mainly manufactured by domestic companies and dedicated to passenger transport. The paper presents the methodology and results for measuring ride comfort, in extent of vibration and noise, at the driver’s stand in new and modernized rail vehicles, according to relevant standards and regulations. The following are described: measurement outcomes, tested vehicles, measuring devices, measuring points and route. The paper also contains information about vibration and noise sources in rail vehicles.

PL

W artykule przedstawiono metody oraz wyniki pomiarów komfortu pracy w zakresie drgań i hałasu na stanowisku maszynisty w nowych i zmodernizowanych elektrycznych zespołach trakcyjnych w świetle obowiązujących przepisów i norm. Opisano wykorzystaną aparaturę pomiarową i miejsca pomiarów. W artykule podano także informacje o możliwych źródłach drgań i hałasu w pojazdach szynowych.

3

Verification of a tram wheel new profile dynamic behaviour

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Staśkiewicz T. , Firlik B.

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tom Vol. 69, No. 1

49--60

EN

This paper is concerned about verification of a tram wheel new profile on multi-body simulation basis. The profile was obtained in an optimization process, which objective function was reduction of gaps occurring between points of contact with rail. The following parameters were checked: derailment coefficient Y/Q, wheelset lateral displacement, number of contact points and wear index. The aim of this work was to determine whether the new wheel profile is suitable for Polish tram networks and if its performance is enhanced in comparison to other profiles being applied. Simulation rides were carried out on tracks with measured geometry. It was found out, that the new profile had significantly better wear properties, but the ride safety was controversial.

PL

Niniejszy artykuł jest poświęcony symulacyjnej weryfikacji dynamicznych własności kół tramwajowych o nowym profilu, który opracowano na drodze optymalizacji kształtu, której funkcją celu była redukcja rozmiarów przerw między punktami kontaktu koła z szyną. Sprawdzono następujące wielkości: współczynnik bezpieczeństwa przeciwko wykolejeniu, przesunięcie poprzeczne zestawu kołowego, spokojność biegu, liczbę punktów styku oraz współczynnik intensywności zużywania. Celem pracy było określenie czy nowy profil może być wdrożony do eksploatacji w polskich sieciach tramwajowych oraz czy jego własności dynamiczne uległy poprawie względem profili obecnie eksploatowanych. Przejazdy symulacyjne były prowadzone na torach o rzeczywistej, zmierzonej geometrii. Zauważono, że nowy profil miał znacznie lepsze właściwości zużyciowe, lecz bezpieczeństwo jazdy było dyskusyjne.