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Combined measurement and simulation of piston ring cylinder liner contacts with a reciprocating long-stroke tribometer
Publication date: Available online 23 June 2021Source: Tribology InternationalAuthor(s): Björn Michelberger, Dirk Jaitner, Andreas Hagel, Patrick Striemann, Benjamin Kröger, Andreas Leson, Andrés Fabián Lasagni
Source: Tribology International - June 25, 2021 Category: Materials Science Source Type: research

Oil film variation and surface damage in the process of reciprocation-oscillation transformation
In this study, optical interferometry experiments were carried out on a ball-disk test rig to study the change of elastohydrodynamic lubrication (EHL) in reciprocation to boundary lubrication (BL) in oscillation for the contacts of pure rolling and simple sliding motions. Then, using an SRV wear tester, the corresponding tribological performance during the transformation from the reciprocating motion to the oscillating motion under simple sliding condition was evaluated. The experimental results show that the BL area in the contact zone gradually increases with the decrease of the stroke length, so that the area of entrapp...
Source: Tribology International - June 26, 2019 Category: Materials Science Source Type: research

Performance evolution of a worn piston ring
Publication date: October 2018Source: Tribology International, Volume 126Author(s): W. Ma, N. Biboulet, A.A. LubrechtAbstractReducing the fuel consumption of a combustion engine has been an important design issue. Engine friction has to be reduced and the piston ring - cylinder liner contact is a major source of friction. However, the piston ring geometry can evolve due to wear, and the ring can acquire a flat part. The current work analytically studies the hydrodynamic friction and load carrying capacity of a twisted parabolic - flat (worn) piston ring. The outcome is presented as a function of twist angle, total width an...
Source: Tribology International - July 10, 2018 Category: Materials Science Source Type: research

Evolutions of cylinder liner surface texture and tribological performance of piston ring-liner assembly
Publication date: Available online 7 July 2018Source: Tribology InternationalAuthor(s): Wieslaw Grabon, Pawel Pawlus, Slawomir Wos, Waldemar Koszela, Michal WieczorowskiAbstractThis paper presents the results of the tribological experiments conducted using an oscillating wear tester under lubricated conditions. Specimen from piston ring slid against counter-specimen from cylinder liner. Various surface textures of cylinder liners resulted from honing and/or plateau honing. Tests were carried out for two normal loads of 100 and 300 N at a temperature of 80 °C, the stroke was 3 mm, the frequency was 10 Hz. Each ex...
Source: Tribology International - July 10, 2018 Category: Materials Science Source Type: research

Performance evolution of a worn piston ring
Publication date: October 2018Source: Tribology International, Volume 126Author(s): W. Ma, N. Biboulet, A.A. LubrechtAbstractReducing the fuel consumption of a combustion engine has been an important design issue. Engine friction has to be reduced and the piston ring - cylinder liner contact is a major source of friction. However, the piston ring geometry can evolve due to wear, and the ring can acquire a flat part. The current work analytically studies the hydrodynamic friction and load carrying capacity of a twisted parabolic - flat (worn) piston ring. The outcome is presented as a function of twist angle, total width an...
Source: Tribology International - July 5, 2018 Category: Materials Science Source Type: research

Effects of cylinder liner surface topography on friction and wear of liner-ring system at low temperature
Publication date: May 2018 Source:Tribology International, Volume 121 Author(s): Wieslaw Grabon, Pawel Pawlus, Slawomir Wos, Waldemar Koszela, Michal Wieczorowski The experiments were carried out using an Optimol SRV5 oscillating wear tester under lubrication. Specimens were cut from gray cast iron cylinder liners honed and/or plateau honed with diamond or ceramic stones. Counter-specimens were cut from chromium-coated compression ring. Short time tests of 30 min duration were conducted at a temperature of −20 °C, with a stroke of 3 mm. In addition, for a few sliding assemblies, durations of tests at the low temp...
Source: Tribology International - February 5, 2018 Category: Materials Science Source Type: research

Effects of lateral harmonic vibrations on film thickness in EHL point contacts
Publication date: January 2018 Source:Tribology International, Volume 117 Author(s): Josef Fryza, Petr Sperka, Ivan Krupka, Martin Hartl Vibrations are an integral part of machine operation and affect every elastohydrodynamically lubricated conjunctions. In the present experimental study, a rolling contact is subjected to lateral-sliding vibrations with short stroke length. Film thickness behaviour is investigated under diverse conditions including rolling speeds, stroke lengths, frequencies, loads, and variety of lubricants. The results obtained under vibrations are compared with the results for corresponding steady stat...
Source: Tribology International - September 21, 2017 Category: Materials Science Source Type: research

A new coupling tribodynamic model of crosshead slipper-guide system and piston skirt-liner system of low-speed marine diesel engines
Publication date: January 2018 Source:Tribology International, Volume 117 Author(s): Rui Li, Xianghui Meng, Youbai Xie In this paper, considering the coupling effects of the crosshead slipper-guide system and the piston skirt-liner system, a new tribodynamic model is established for the low-speed two-stroke marine diesel engine. Firstly, a dynamic model including the crosshead slipper, the piston, the piston rod, and the crosshead pin is proposed. Then, considering the disciplinary coupling between the dynamic model and the lubrication models, the stiff and nonlinear tribodynamic model is solved with the modified extended...
Source: Tribology International - September 15, 2017 Category: Materials Science Source Type: research

Lubrication performance of an ammonium cation-based ionic liquid used as an additive in a polar oil
Publication date: December 2017 Source:Tribology International, Volume 116 Author(s): J.L. Viesca, M.T. Mallada, D. Blanco, A. Fernández-González, J. Espina-Casado, R. González, A. Hernández Battez This paper studies the tribological behavior of the ionic liquid methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([N1888][NTf2]) as additive at different concentrations (1.25, 2.50, 3.75 and 5.00 wt%) in a polar base oil (diester). A tribometer using a ball-on-disk reciprocating configuration under fully flooded lubrication was used at a frequency of 15 Hz, at three different loads (40, 80 and 120 N), stroke len...
Source: Tribology International - August 9, 2017 Category: Materials Science Source Type: research

Looking into a laser textured piston ring-liner contact
Publication date: November 2017 Source:Tribology International, Volume 115 Author(s): Sorin-Cristian Vlădescu, Alessandra Ciniero, Khizer Tufail, Arup Gangopadhyay, Tom Reddyhoff This paper presents an experimental study into the flow behaviour of lubricant in a reciprocating contact simulating a piston ring–cylinder liner pair. The aim was to understand the effects of cavitation, starvation and surface texture, as well as the interaction between these, in order to improve automotive engine performance. A custom-built test rig was used, in which a section of piston ring is loaded against a reciprocating, laser-textured...
Source: Tribology International - May 29, 2017 Category: Materials Science Source Type: research

Tribocorrosion behavior of hot pressed CoCrMo alloys in artificial saliva
Publication date: May 2016 Source:Tribology International, Volume 97 Author(s): M. Buciumeanu, A. Bagheri, J.C.M. Souza, F.S. Silva, B. Henriques The aim of this work was to investigate the influence of the processing conditions on the tribocorrosion behavior of hot pressed CoCrMo biomedical alloys. Several samples were processed as a function of different processing temperatures (900, 1000 and 1100°C) and times (10, 30 and 60min). Tribocorrosion tests were carried out in artificial saliva at 37°C, under 1N normal load, 1Hz frequency and 3mm stroke length. Open circuit potential was measured. The worn surfaces wer...
Source: Tribology International - February 20, 2016 Category: Materials Science Source Type: research

Tribological property investigation on a novel pneumatic actuator with integrated piezo actuators
This article investigates vibrations of the seal generated by integrated piezo actuators to reduce friction force. For this, two piezoelectric stacks are integrated in the cylinder and used to excite vibration modes. This concept was studied in a compact cylinder pneumatic actuator with a bore diameter of 5mm and a stroke of 10mm. Dry friction measurement shows a 52% reduction from the original friction force at a driving frequency of 18.29kHz and vibration amplitude of 0.05μm. In the wet friction experiments, the friction force can be reduced by 54% from the original wet friction with vibrations at amplitude of 0.04μm.
Source: Tribology International - February 20, 2015 Category: Materials Science Source Type: research