A Spectrographic Sampling Method for Quick Assessment of Cylinder and Piston Ring Wear

1968 ◽  
Vol 90 (1) ◽  
pp. 43-48
Author(s):  
H. U. Wisniowski ◽  
D. R. Jackson

A simple, inexpensive, and rapid method of assessing cylinder and piston ring wear was developed. A small sample of the oil which lubricates the cylinder wall and piston rings was drawn off through a small hole in the cylinder wall. The sample was then analyzed spectrographically. Changes in wear resulting from changes in cylinder liner materials, fuels, lubricating oils, and other operating conditions were investigated. The method was found useful especially in cases of drastic differences in the wear rates. Selected examples of these studies are reported.

2019 ◽  
Vol 72 (1) ◽  
pp. 101-108
Author(s):  
Jun Sun ◽  
Xiao Zhang ◽  
Jianxiong Zhu ◽  
Yaming Gao ◽  
Hu Wang ◽  
...  

Purpose Currently, lubrication analysis of piston ring is generally done under engine rated operating condition. However, the engine (such as the vehicle engine) does not always operate in rated operating condition, and its operating condition changes frequently in actual use. In addition, the lubrication status of piston ring is generally assumed as the flooded lubrication or a certain form of poor lubrication in most of the lubrication analysis. Design/methodology/approach In this paper, based on the equations about the flow rate of lubricating oil and the variation of control volume, the flow model of lubricating oil in the piston ring-cylinder liner conjunction is established. The lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done, in which the lubricating oil at the inlet of piston ring is considered as the lubricating oil attached on the relevant location of cylinder wall after the piston ring moves over at the previous stroke. Findings There is remarkable difference for the lubrication characteristics of the piston ring under different engine operating conditions. The worst lubrication status of piston ring may not take place under engine rated operating condition. Originality/value In this paper, based on the measured engine cylinder pressure, the lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done in which the lubricating oil supply condition at the inlet of piston ring is considered. The results of this paper are helpful for the design and research of engine piston ring-cylinder liner conjunction.


Author(s):  
Yang Hu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Jiazheng Fan

The cylinder liner surface finish, which is commonly produced using the honing technique, is an essential factor of engine performance. The characteristics of the texture features, including the cross-hatch angle, the plateau roughness and the groove depth, significantly affect the performance of the ring pack–cylinder liner system. However, due to the influence of the honed texture features, the surface roughness of the liner is not subject to Gaussian distribution. To simulate the mixed lubrication performance of the ring–liner system with non-Gaussian roughness, the combination of a two-scale homogenization technique and a deterministic asperities contact method is adopted. In this study, a one-dimensional homogenized mixed lubrication model is established to study the influence of groove parameters on the load-carrying capacity and the frictional performance of the piston ring–liner system. The ring profile, plateau roughness, and operating conditions are taken into consideration. The main findings are that for nonflat ring, shallow and wide groove textures are beneficial for friction reduction, and there exists an optimum groove density that makes the friction minimum; for flat ring, wide and sparse grooves help improving the tribological performance, and there exists an optimum groove depth that makes the friction minimum.


2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal

Abstract This study investigated the use of biodiesel (B100) and baseline mineral diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel’s compatibility and durability issues with modern common rail direct injection (CRDI) engine-powered vehicles. Two identical vehicles were operated for 30,000 km under identical operating conditions during a field-trial using biodiesel (B100) and mineral diesel. Exhaustive experimental results from this series of tests are divided into four sections, and this is the third paper of this series of four papers, which covers comparative feasibility and wear analyses, underlining the effect of long-term use of biodiesel on wear of cylinder liner and piston rings compared to baseline mineral diesel-fueled vehicle. Surface microstructures at three locations of the cylinder liner were evaluated using scanning electron microscopy (SEM). Wear was found to be relatively lower at all locations of liners from biodiesel-fueled vehicle compared to diesel-fueled vehicle. Surface roughness of cylinder liners measured at different locations showed that it reduced by ∼30–40% at top dead center (TDC), ∼10–20% at mid-stroke, and ∼20–30% at bottom dead center (BDC) for both vehicles, showing higher wear close to TDC compared to mid-stroke and BDC locations. Loss of piston-ring weight was significantly lower for biodiesel-fueled vehicle. Engine tear-down observations and carbon deposits on various engine components were recorded after the conclusion of the field trials. During these field-trials, engine durability-related issues such as fuel-filter plugging, injector coking, piston-ring sticking, carbon deposits in the combustion chamber, and contamination of lubricating oils were found to be relatively lower in biodiesel-fueled vehicle. Overall, no noticeable durability issues were recorded because of the use of biodiesel in CRDI engine-powered vehicle.


Author(s):  
Gurtej Singh ◽  
Mohammad Farooq Wani ◽  
Mohammad Marouf Wani

Friction and wear are the main causes of energy dissipation in automotive engines. To minimize the frictional power losses, it is extremely important to improve the tribological characteristics of ring/liner assembly which accounts for almost 40–50% frictional power losses. The present study attempts to mitigate friction and wear of the ring/liner tribo-pair using GNP/SAE 15W40 nano-lubricant. To simulate the ring/liner interface, the tribological performance of nano-lubricants was assessed using a tribometer based on ASTMG181 standard under various operating conditions. The coefficient of friction (COF) and wear rate lowered using graphene nano-lubricants (GNL). The tribological results showed that friction coefficient, wear rate, and surface roughness of piston ring improved in the range 17.71%–42.33%, 25%–40.62%, and 61%, respectively, under GNL lubricating conditions during the boundary lubrication. Further, the characterization of wear tracks of piston ring and cylinder liner confirmed tribo-film formation on worn surfaces resulting in decreased COF and wear rate.


2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093084
Author(s):  
Brahim Menacer ◽  
Mostefa Bouchetara

For different operating conditions of an internal combustion engine, the piston–ring–liner compartment represents one of the largest sources of friction and power losses. The aim of this article is to evaluate the effect of the compression ring profile on the main tribological performance of the lubricant in a four-stroke diesel engine. A one-dimensional analysis was developed for the hydrodynamic lubrication between the compression piston ring and the cylinder wall. A numerical method was applied to analyze the influence of different ring geometrical designs during the working cycle on oil film thickness, frictional force, and power losses. Our predicted results were validated with the Takiguchi data of a previous study, and they have shown a good agreement. The results in the current analysis demonstrated that the ring geometry profile, the engine speed, and load have a remarkable effect on oil film thickness, friction force, and friction power losses between the top ring and cylinder liner. Therefore, it would help in reducing friction as well as making a contribution to the improvement of engine performance such as torque, efficiency, and fuel consumption.


Author(s):  
H. Xu ◽  
M. D. Bryant ◽  
R. D. Matthews ◽  
T. M. Kiehne ◽  
B. D. Steenwyk ◽  
...  

This paper presents two piston ring and cylinder liner lubrication models and compares the friction predictions against the experimental results from a corresponding bench test. The first model aims to solve the average Reynolds equation with corrective flow factors, which describe the influence of surface irregularities on the lubricant flow under mixed lubrication condition. The second model takes account of the lubricant film rupture and cavitation. Meanwhile, a stochastic rough contact sub-model quantifies the relation between contact pressure and mean surface separation in both cases. Numerical results on the top compression ring simulation show that both models capture hydrodynamic, mixed, and boundary lubrication regimes, which depend on the real surface topographies of the piston ring and the cylinder liner. Whenever hydrodynamic action is insufficient to maintain the equilibrium position of the ring, the restoring force will be augmented by multi-asperity contacts lubricated by a thin boundary film. Total friction will originate mainly from shearing of viscous lubricant and shearing of asperity conjunctions. The purpose of this modeling effort is to compare both lubrication models to data from an experimental test-rig. This test rig eliminates many of the factors that can make analysis of predictions for real engine operating conditions difficult.


Author(s):  
Mohammed Kamal Ahmed Ali (M.K.A. Ali)

One of the most important objectives of the studies worldwide is to improve the performance of automotive engines to reduce fuel consumption and environmental pollution. Accordingly, the principal motivation of this research study is improving the tribological behavior of the piston ring/cylinder liner interfaces as a promising and straightforward approach in automotive fuel economy and increasing engine durability using Al2O3 and TiO2 nanomaterials as smart nano-lubricant additives that adapted to different operating conditions by replenishing mechanisms anti-friction and anti-wear in automotive engines.


2014 ◽  
Vol 66 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Jian Zhan ◽  
Mingjiang Yang

Purpose – The purpose of this study was to develop a new approach using a pulse YAG laser with rational power density and pulse width to texture desired discrete distribution morphology on the cylinder wall. Design/methodology/approach – Variational rules of the effects of these three parameters were found by calculating the oil film on the cylinder/piston ring system. The experiment results were compared between laser texturing cylinders and conventional honing cylinders. Findings – It was found that the coefficient of friction and wear rate of laser texturing cylinders were reduced by 50 and 85.7 per cent, respectively, and the piston ring wear rate was decreased by 50 per cent under full lubrication condition. Under starved lubrication condition, the cylinder liner wear was reduced by 34.3 per cent. Originality/value – The effectiveness of which was determined by three control parameters: depth-to-diameter ratio, area density and distribution angle of the dimples.


Author(s):  
Peder Klit ◽  
Anders Vo̸lund

A very important condition for describing the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. It is often assumed that piston rings operate under fully flooded conditions, but this is not the case in real life operation. In large two-stroke engines the cylinder oil is supplied periodically to the bearing at discrete locations on the cylinder liner. The shifting in lubrication regimes and the non-uniform oil distribution opens for the possibility of starved conditions for the piston ring bearing. Therefore it is important to measure the oil distribution on the liner as a function of the operating conditions. The amount of lubricant available is reflected in the friction absorbed in the bearing. The paper describes an investigation of the tribological condition between a piston ring and cylinder. A test apparatus is used to study the interaction between a piston ring and a cylinder liner.


Author(s):  
Anastasios Zavos ◽  
Pantelis G Nikolakopoulos

This paper presents a thorough experimental study of piston assembly friction and noise in a single-cylinder motorbike engine operating at low speeds. The friction of the piston ring pack is evaluated using a foil strain gauge with minimal cylinder modification on the thrust side. The technique involves transmitting deformations through the cylinder bore and recording reflections from the lubricated interface as the piston assembly passes. Under these conditions, the piston side forces and the thermal deformations on the output side of the strain gauge sensor are critical. Therefore, the proposed methodology is designed under controlled operating conditions. The overall deformation of the piston assembly is analysed to measure the primary reflection due to friction between the piston assembly and the cylinder wall. Simultaneously, the piston assembly noise is recorded on the thrust side of the engine block using a microphone. Taking measured noise data into account, possible piston slap events resulting from varied engine speeds are taken into account using continuous wavelet signal analysis. The calibration procedure for both tests is also illustrated. The measured friction results show that the strain gauge technique is a challenging work in providing realistic results to enhance current technology. For low engine speeds, a higher contribution is noted by boundary friction at the top dead centre reversal, extending to the position of maximum combustion pressure in the power stroke. Furthermore, the main contribution of the piston slap is estimated at the thrust side when the piston assembly passes at the beginning of the combustion stroke. These results can also be attributed as data to validate piston ring models in terms of friction and piston slap.


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