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1

Analysis of Uncontrolled Wear in the Area of a Belleville Spring of a Friction Torsional Vibration Damper in a Motor Vehicle Clutch

Formela Michał Tomasz, Łubiński Jacek Igor

Tribologia

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2024

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nr 1

31--41

EN

The article describes the problem of excessive tribological wear of a torsional vibration damper built into a single-disc friction clutch of a truck vehicle. In contrast to the controlled, design-based wear of damper’s friction rings, i.e., wear whose kinetics are known and predictable, uncontrolled wear at Belleville spring contact surfaces effects in a premature decrease in the damper’s friction torque and, consequently, loss of durability. As a result of the analyses and experimental work, the causes of accelerated wear were identified. Sets of springs and friction rings from the 10 used vibration dampers that worked under similar operating conditions but with different operating periods were used as the basic research material. The influence of abrasive wear of Belleville springs on their load-deflection characteristic was identified. A comparative analysis of the characteristics of the new spring and the used springs is also presented to illustrate changes in the axial load in the assemblies of the analyzed dampers.

PL

W artykule opisano problem nadmiernej intensywności zużycia ściernego tłumika drgań skrętnych, wbudowanego w jednotarczowe sprzęgło cierne pojazdu ciężarowego. W przeciwieństwie do kontrolowanego konstrukcyjnie przewidzianego zużywania się pierścieni ciernych tłumika, tj. zużycia, którego kinetyka jest znana i przewidywalna, niekontrolowane zużycie powierzchni oporowych talerzowej sprężyny dociskowej skutkuje przedwczesnym spadkiem momentu tarcia tłumika, a co za tym idzie, utratą jego trwałości. W wyniku przeprowadzonych analiz i prac doświadczalnych zidentyfikowano przyczyny przyspieszonego zużycia. Jako podstawowy materiał badawczy wykorzystano zestawy sprężyn oraz pierścieni pochodzących z 10 używanych tłumików drgań, które pracowały w podobnych warunkach eksploatacyjnych, ale różniących się okresem eksploatacji. Zidentyfikowano wpływ zużycia ściernego sprężyn dociskowych na charakterystyki siły w funkcji ugięcia. Przedstawiono również analizę porównawczą charakterystyki nowej sprężyny i sprężyn używanych w celu pokazania zmian wartości sił osiowych w złożeniach analizowanych tłumików.

2

Evaluation of Wear Resistance of Functional Composite Polymeric Materials and Durability of Metal-Polymer Bearings

Chernets Myron, Świć Antoni, Kornienko Anatolii, Yurchuk Alina

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 2

258--267

EN

A method of tribological testing of models with such sliding friction using a simple pin-on-disc mechanism was presented. Wear resistance indicators of unfilled polyamides PA6, PA66 and composites based on polyamide PA6+30GF, PA6+30CF, PA6+MoS2, PA6 and oil coupled with steel C45 are determined. They, as polymeric materials with the property of self-lubrication, they are often used in metal-polymer dry friction bearings. Based on them, wear resistance characteristics of these polymeric materials at sliding friction are established. They are used as basic parameters for developed by authors mathematical model of material wear kinetics at sliding friction and analytical research method of metal-polymer sliding bearings research. For comparative assessment of wear resistance of the investigated polymeric materials, their wear resistance diagrams are constructed. Thef show the functional dependence of wear resistance on specific friction forces. It is proved that the wear resistance of materials nonlinearly depends on specific pressure, i.e., the specific friction forces. Qualitative and quantitative influence of the type and structure of fillers (which improve the tribological properties of the base polymer PA6) on their wear resistance has been established. The forecast estimation of durability of metal polymer bearings made of the specified polyamides by the author's method of calculation taking into account their various wear resistance, characteristics of elasticity and conditions of dry friction is carried out. The research results are presented graphically, which facilitates their understanding and analyses.

3

Wpływ nacisku, prędkości ślizgania i twardości na zużycie przy suchym tarciu stali na obręcze kół kolejowych

Witaszek M., Witaszek K.

Tribologia

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2009

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nr 4

267-274

PL

W artykule przedstawiono wyniki badań zużycia wybranych trzech stali węglowych. Badania przeprowadzono na zmodyfikowanym stanowisku Timkena, przy suchym tarciu ślizgowym. Wyniki badań pozwoliły na określenie zależności intensywności zużywania badanych stali od wybranych parametrów charakteryzujących własności materiału (twardość stali) i warunki współpracy (nacisk i prędkość ślizgania). Zależności te opisano za pomocą równania wykładniczego. Wykorzystano je wraz z wynikami badań metalograficznych do analizy merytorycznej otrzymanych wyników badań zużycia.

EN

In this article, wear test results of three carbon steels (B6, C54 and C55) are presented. These tests have been performed on a modified Timken wear-testing machine in dry sliding conditions. To obtain an initial point contact (like in wheel – rail system), two cylinders with perpendicular axes have been used as elements of the tested pair. One of them had a motionless specimen, and the second one had a counter-specimen rotated around its axis. Volume loss and apparent contact area vs. load, sliding speed, and sliding distance were determined. On the basis of these results, the linear wear rate and contact pressure were calculated. Results of these calculations have been utilised to determine the influence of pressure, sliding speed, and material hardness on the wear rate of the tested steels. These influences have been mathematically described with an exponential function, which was used to analyse the wear behaviour of the researched materials. Optical microscopic observations of worn surfaces were carried out to study wear mechanisms.

4

Model tarcia suchego w procesie manipulowania potokiem ładunków jednostkowych

Piątkowski T.

Logistyka

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2009

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nr 6

PL

W artykule przedstawiono wyniki badań numerycznych procesu manipulowania (sortowania pozycjonowania) strumienia ładunków jednostkowych (prostopadłościennych paczek) transportowanych na przenośnikach. Celem prowadzonych badań jest określenie wpływu przyjętych modeli tarcia oraz charakterystyk współczynnika tarcia na przebieg symulacji modeli procesu manipulowania ładunków. Na podstawie uzyskanych danych wynika, że szczególnie podatny na rodzaj zastosowanego modelu sił tarcia jest model procesu manipulowania, który przebiega w zakresie małych prędkości poślizgu przez znaczną część trwania procesu.

EN

The paper deals with the numeric tests of handling process (sorting and positioning) of unit loads stream (cubiform packages) transported on conveyors. The estimation of influence of assumed friction models and the characteristics of friction coefficient on the course of simulation of handling process of loads is the main aim of performed tests. On the basis of obtained data, results that particularly susceptible to the kind of applied friction model is the handling process which runs with small rubbing speed by the considerable part of the process duration.

5

Low friction and wear resistant coating systems on Ti6Al4V alloy

Wendler B. G., Pawlak W.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 26, nr 2

207-210

EN

Purpose: Development of an original multiplex hybrid treatment of Ti6Al4V alloy: diffusion hardening+intermediate hard gradient TiCxNy layer with use of continuous CAE+top low friction and wear resistant hard amorphous a-C layer with use of pulsed CAE method. Design/methodology/approach: Ti6Al4V substrates were diffusion hardened with interstitial O or N atoms with use of glow discharge plasma in the atmosphere Ar+O2 or Ar+N2. Next they were deposited with a hard gradient TiCxNy layer and with a hard amorphous a-C coating as the top one. The morphology, microstructure, chemical and phase composition, chemical bonds, microhardness and tribological properties during dry friction of the alloy after multiplex treatment have been investigated with use of SEM, EDS, XRD, XPS, Vickers diamond indenter and ball-on-plate test. Findings: An important increase of hardness of the near surface zone of the Ti6Al4V alloy has been achieved (from ∼ 350VHN to ∼ 1000 VHN), good adhesion between the gradient TiCxNy coating and the Ti6Al4V substrate as well as an important decrease of dry friction coefficient (down to ∼ 0.15) and a substantial increase of the resistance to wear (up to two orders of magnitude in comparison with non treated Ti alloy). Research limitations/implications: The research will be continued on greater number of specimens and against other counterbodies. Practical implications: It looks like that the Ti alloys can be used as mobile parts of machines due to high resistance to wear and low friction. Originality/value: A novel original multiplex hybrid treatment of Ti alloys has been developed at the Lodz University of Technology.