Piston Ring Designs for Reduce Friction

Hill, Stephen H.; Newman, B. A.

doi:10.4271/841222

Cited by 29 publications

(50 citation statements)

References 2 publications

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“…A typical combustion gas pressure curve is shown in Figure 3. Study of this point is of further importance as the combustion gas force (Hill and Newman, 1985) is one of the main contributors to the cylinder liner deformation. The measured shape of the liner can be described using a Fourier series: (1) where r is the average (nominal) bore radius.…”

Section: Ring Bore Conformabilitymentioning

confidence: 99%

“…In this study, the conformability criteria given by Mueller, Tomanik, Dunaevsky, and Hill and Newman are studied (see Introduction). Table 1 compares these four conformability analyses as described by Bardzimashvili, et al (2005) and Newman and Hill (1985). Hill and Newman (1985) The parameter K in Table 1 is called the ring conformability coefficient (or factor) and is defined as:…”

Section: Ring Bore Conformabilitymentioning

confidence: 99%

“…In the case of Hill and Newman (1985) conformability relation, this factor is expressed as: (4) where d is radial thickness of the ring.…”

Section: Saementioning

confidence: 99%

“…The second order distortion of a cylinder refers to its ovality, whilst the third and fourth orders arise from machining and excessive tightening of the cylinder head bolts, respectively (Bardzimashvili et al, 2005). Hill and Newman (1985) introduced the concept of 'ring conformability factor' in order to quantify the ability of a ring to seal a given bore distortion. Using an empirical relationship, they were able to describe the radial deformation for a cylinder at given order which can be sealed by a ring with a known conformability factor.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analytical Evaluation of Fitted Piston Compression Ring: Modal Behaviour and Frictional Assessment

Baker¹,

Rahnejat²,

Rahmani³

et al. 2011

SAE Technical Paper Series

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Section: Ring Bore Conformabilitymentioning

confidence: 99%

Section: Ring Bore Conformabilitymentioning

confidence: 99%

“…In the case of Hill and Newman (1985) conformability relation, this factor is expressed as: (4) where d is radial thickness of the ring.…”

Section: Saementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Analytical Evaluation of Fitted Piston Compression Ring: Modal Behaviour and Frictional Assessment

Baker¹,

Rahnejat²,

Rahmani³

et al. 2011

SAE Technical Paper Series

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“…MIT's computer models [1][2][3][4][5] have been applied to target the most important contributors to friction in the piston-cylinder assembly of the engine. Specifically, three models were applied to analyze the behavior of the piston rings and these are described in some detail in the section that follows.…”

Section: Overviewmentioning

confidence: 99%

Low-Engine-Friction Technology for Advanced Natural-Gas Reciprocating Engines

Wong¹,

Tian²,

Moughon³

et al. 2004

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This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. An iterative process of simulation, experimentation and analysis, are being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various lowfriction strategies and ring-design concepts have been explored, and engine experiments have been done on a full-scale Waukesha VGF F18 in-line 6 cylinder power generation engine rated at 370 kW at 1800 rpm.Current accomplishments include designing and testing ring-packs using a subtle topcompression-ring profile (skewed barrel design), lowering the tension of the oil-control ring, employing a negative twist to the scraper ring to control oil consumption. Initial test data indicate that piston ring-pack friction was reduced by 35% by lowering the oil-control ring tension alone, which corresponds to a 1.5% improvement in fuel efficiency. Although small in magnitude, this improvement represents a first step towards anticipated aggregate improvements from other strategies. Other ring-pack design strategies to lower friction have been identified, including reduced axial distance between the top two rings, tilted top-ring groove. Some of these configurations have been tested and some await further evaluation. Colorado State University performed the tests and Waukesha Engine Dresser, Inc. provided technical support.Key elements of the continuing work include optimizing the engine piston design, application of surface and material developments in conjunction with improved lubricant properties, system modeling and analysis, and continued technology demonstration in an actual full-sized reciprocating natural-gas engine.-3 -

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