Performance Evaluation of Piston Compression Ring Through Accelerated Wear in Engine Tests

2012 ◽  
Author(s):  
Nicholas Morris ◽  
Homer Rahnejat ◽  
Ramin Rahmani ◽  
Paul King ◽  
Brian Fitzsimons
Keyword(s):  
Mechanical Property ◽  
Piston Ring ◽  
Tribological Performance ◽  
Engine Test ◽  
Average Flow ◽  
Wear Process ◽  
Fundamental Knowledge ◽  
Compression Ring ◽  
Method Of Solution ◽  
Cylinder Bore

Both the piston ring and cylinder bore experience wear throughout their life cycle. Therefore change occurs in the geometrical profile and topography of the ring. In addition, coating on the ring is also subject to wear, thus altering the physical/mechanical property of the contacting surface. These changes affect the tribological performance of the ring-bore conjunction. Geometrical changes often alter the ring contacting profile, which affects the entrainment of the lubricant into the conjunction. This can affect the regime of lubrication, thus mechanisms that contribute to friction. Wear of surfaces also plays some role in boundary friction in terms of topographical changes as well as surface properties such as hardness and asperity shear strength. Most analysis does not take into account changes in tribological conditions which occur as the result of these salient changes in practice. The paper intends to bridge this gap in the fundamental knowledge and provide explanations for some in-field experiences noted with wear of a compression ring in a typical engine test. The method of solution used is based on the average flow factors which are indicative of entrainment of the lubricant through the rough ring-bore conjunction. This approach was initiated by Patir and Cheng, for which realistic topographical parameters according to the stage of the wear process is included. Changes in friction and fuel energy consumed are predicted.

Wear Model for Piston Ring and Cylinder Bore System

2005 ◽  
Author(s):  
Yunchao Qiu ◽  
Qian Zou ◽  
Gary C. Barber ◽  
Harold E. McCormick ◽  
Dequan Zou ◽  
...  
Keyword(s):  
Piston Ring ◽  
Thickness Distribution ◽  
Matrix Ring ◽  
Experimental Investigations ◽  
General Tendency ◽  
Wear Model ◽  
Wear Process ◽  
The Matrix ◽  
Surface Profiles ◽  
Cylinder Bore

A new wear model for piston ring and cylinder bore system has been developed to predict wear process with high accuracy and efficiency. It will save time and cost compared with experimental investigations. Surfaces of ring and bore were divided into small domains and assigned to corresponding elements in two-dimensional matrix. Fast Fourier Transform (FFT) and Conjugate Gradient Method (CGM) were applied to obtain pressure distribution on the computing domain. The pressure and film thickness distribution were provided by a previously developed ring/bore lubrication module. By changing the wear coefficients of the ring and bore with accumulated cycles, wear was calculated point by point in the matrix. Ring and bore surface profiles were modified when wear occurred. The results of ring and bore wear after 1 cycle, 10 cycles and 2 hours at 3600 rpm were calculated. They coincided well with the general tendency of wear in a ring and bore system.

scholarly journals Effect of cylinder de-activation on the tribological performance of compression ring conjunction

2016 ◽  
Vol 231 (8) ◽  
pp. 997-1006 ◽  
Author(s):  
SR Bewsher ◽  
R Turnbull ◽  
M Mohammadpour ◽  
R Rahmani ◽  
H Rahnejat ◽  
...  
Keyword(s):  
Power Loss ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Cylinder Liner ◽  
Combustion Efficiency ◽  
Tribological Performance ◽  
Power Losses ◽  
Cylinder Deactivation ◽  
Compression Ring ◽  
Transient Thermal

The paper presents transient thermal-mixed-hydrodynamics of piston compression ring–cylinder liner conjunction for a 4-cylinder 4-stroke gasoline engine during a part of the New European Drive Cycle (NEDC). Analyses are carried out with and without cylinder de-activation technology in order to investigate its effect upon the generated tribological conditions. In particular, the effect of cylinder deactivation upon frictional power loss is studied. The predictions show that overall power losses in the piston–ring cylinder system worsen by as much as 10% because of the increased combustion pressures and liner temperatures in the active cylinders of an engine operating under cylinder deactivation. This finding shows the down-side of this progressively employed technology, which otherwise is effective in terms of combustion efficiency with additional benefits for operation of catalytic converters. The expounded approach has not hitherto been reported in literature.

scholarly journals The Effect of Honing Angle and Roughness Height on the Tribological Performance of CuNiCr Iron Liner

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 487 ◽  
Author(s):  
Ma ◽  
Liu ◽  
Wang ◽  
Wang ◽  
Huang ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Friction And Wear ◽  
Piston Ring ◽  
Friction Pair ◽  
Tribological Performance ◽  
Roughness Height ◽  
Roughness Parameters ◽  
Slight Effect ◽  
Wear Process ◽  
Worn Surface

This work investigated the effect of honing morphologies of CuNiCr iron liner on its tribological properties sliding against the Cr-Al2O3 coated piston ring. The worn surface morphology and elements distribution as well as the wear behaviors of CuNiCr iron liner were analyzed to explore the influencing of the honing angle and roughness height on the friction and wear resistance. The results show that the optimized honing angle and roughness can improve the tribological performance of the iron liner, and different tribological characteristics are closely related to different roughness parameters. The wear process of the CuNiCr iron liner against Cr-Al2O3 coated piston rings in sequence was platform flattening, plastic flow, growth of the flakes on the platform edge and flakes debonding. For the smooth surface, the plastic deformed flakes were much fewer due to the low height of the platforms, thus the grooves were not fully filled and there was a slight effect of the debonded debris on the friction pair.

Analysis of Tribological Performance of Piston Ring Lubrication

2011 ◽  
Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Power Loss ◽  
Piston Ring ◽  
Design Parameters ◽  
Oil Film ◽  
Starved Lubrication ◽  
Piston Ring Lubrication ◽  
Cylinder Bore ◽  
Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

Detailed analysis of piston secondary motion and tribological performance

2019 ◽  
Vol 21 (9) ◽  
pp. 1647-1661 ◽  
Author(s):  
Cristiana Delprete ◽  
Abbas Razavykia ◽  
Paolo Baldissera
Keyword(s):  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Hydrodynamic Pressure ◽  
Tribological Performance ◽  
System Of Nonlinear Equations ◽  
Piston Skirt ◽  
Wide Range ◽  
Secondary Motion ◽  
Piston Ring Pack ◽  
Ring Pack

This article presents a detailed analytical model to evaluate piston skirt tribology under hydrodynamic lubrication. The contribution of the piston ring pack lubrication has been taken into account to study piston secondary motion and tribological performance. A system of nonlinear equations comprising Reynolds equation and force equilibrium is solved to calculate piston ring pack friction force and its moment about wrist pin axis. Instantaneous minimum oil film thickness at piston ring/liner interface has been estimated considering different boundary conditions: full Sommerfeld, oil separation, and Reynolds cavitation and reformation. The ring pack model has capability to be used for a wide range of ring face profiles under boundary and hydrodynamic lubrication. Piston secondary motion is evaluated using lubrication theory and equilibrium of forces and moments, to examine the effect of wrist pin location, piston skirt/liner clearance, and oil rheology. Numerical method and finite difference scheme have been used to define piston eccentricity and hydrodynamic pressure acting over the skirt.

A Study on Lubrication Characteristics between Piston Ring and Cylinder Bore of Bent-Axis Type Piston Pump

2009 ◽  
pp. 136-139
Author(s):  
Jae-Youn Jung ◽  
Ihn-Sung Cho ◽  
Il-Hyun Beak ◽  
Hyun-Il Shin ◽  
Jae-Cheon Jo ◽  
...  
Keyword(s):  
Piston Ring ◽  
Piston Pump ◽  
Lubrication Characteristics ◽  
Cylinder Bore

Influence of positive texturing on friction and wear properties of piston ring-cylinder liner tribo pair under lubricated conditions

2019 ◽  
Vol 71 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Venkateswara Babu P. ◽  
Ismail Syed ◽  
Satish Ben Beera
Keyword(s):  
Wear Resistance ◽  
Internal Combustion Engine ◽  
Friction And Wear ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Tribological Performance ◽  
Friction Reduction ◽  
Content Type

Purpose In an internal combustion engine, piston ring-cylinder liner tribo pair is one among the most critical rubbing pairs. Most of the energy produced by an internal combustion engine is dissipated as frictional losses of which major portion is contributed by the piston ring-cylinder liner tribo pair. Hence, proper design of tribological parameters of piston ring-cylinder liner pair is essential and can effectively reduce the friction and wear, thereby improving the tribological performance of the engine. This paper aims to use surface texturing, an effective and feasible method, to improve the tribological performance of piston ring-cylinder liner tribo pair. Design/methodology/approach In this paper, influence of positive texturing (protruding) on friction reduction and wear resistance of piston ring surfaces was studied. The square-shaped positive textures were fabricated on piston ring surface by chemical etching method, and the experiments were conducted with textured piston ring surfaces against un-textured cylinder liner surface on pin-on-disc apparatus by continuous supply of lubricant at the inlet of contact zone. The parameters varied in this study are area density and normal load at a constant sliding speed. A comparison was made between the tribological properties of textured and un-textured piston ring surfaces. Findings From the experimental results, the tribological performance of the textured piston ring-cylinder liner tribo pair was significantly improved over a un-textured tribo pair. A maximum friction reduction of 67.6 per cent and wear resistance of 81.6 per cent were observed with textured ring surfaces as compared to un-textured ring surfaces. Originality/value This experimental study is helpful for better understanding of the potency of positive texturing on friction reduction and wear resistance of piston ring-cylinder liner tribo pair under lubricated sliding conditions.

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