A Comparison of the Total Capacitance and Total Resistance Techniques for Measuring the Thickness of Journal Bearing Oil Films in an Operating Engine

Spearot, James A.; Murphy, Chester K.

doi:10.4271/880680

Cited by 26 publications

(8 citation statements)

References 8 publications

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“…It has been stated earlier that there is conflicting information in the literature (Spearot and Murphy, 1988, Choi, et al, 1992, Bates, et al, 1990 regarding the effect of cavitation on the measured M B O R . Bearing distortion is also thought to cause significant errors.…”

Section: Effect Of Cavitation and Bearing Non-circularitymentioning

confidence: 96%

Comparison between Theoretical Calculations and Oil Film Thickness Measurements Using the Total Capacitance Method for Crankshaft Bearings in a Firing Engine

Paranjpe

Tseregounis

Viola

2000

Tribology Transactions

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Section: Effect Of Cavitation and Bearing Non-circularitymentioning

confidence: 96%

Comparison between Theoretical Calculations and Oil Film Thickness Measurements Using the Total Capacitance Method for Crankshaft Bearings in a Firing Engine

Paranjpe

Tseregounis

Viola

2000

Tribology Transactions

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“…In addition, the error introduced by cavitation is also relatively smaller in the capacitance technique, and as a result, this approach has gained more prevalence between the methods. A good summary of the issues, which were identified between the two techniques, was covered by Spearot and Murphy [16].…”

Section: Film Thickness Measurementsmentioning

confidence: 99%

“…Critically with the early work, capturing and storing of sufficient data were problematical. For example, Spearot and Murphy [16] highlight that they were only able to measure one point every 14.1 of crank revolution. Therefore, what is normally reported is some kind of average data that shows the minimum film thickness.…”

Section: Film Thickness Measurementsmentioning

confidence: 99%

Fuel economy in heavy duty diesel engines. Part 1: measurement of oil film thickness on an operating engine

Smith¹,

Sutton²

2011

Proceedings of the Institution of Mechanical Engineers, Part J:

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Ever increasing pressure to develop engine oils to enhance vehicle fuel economy has resulted in a trend of decreasing finished fluid viscosity. Impressive fuel economy improvements have been yielded through the application of these lower viscosity fluids without compromising component wear, principally due a combination of improvements in engine design, manufacture and additive packages. However, component assemblies such as journal bearings rely on fluid film separation to function effectively. If the viscosity is reduced below a critical value, the component will no longer reside in the fluid film lubrication regimes and will inevitably operate in the regimes of contact. Without radical redesign of the assembly, or advanced lubricant formulation, this will inevitably result in catastrophic engine failure. This article describes the development of an ultrasonic system to measure film thickness in main engine bearings under firing conditions. This unobtrusive method of measuring film thickness in operating contacts has been applied to the main bearings of operating diesel engines. Preliminary measurements were taken during dynamic engine ramping to identify the thinnest operating film condition. Further film measurements were taken at this condition with the engine running on engine oils with varying bulk oil viscosity.

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“…T h e method of measuring capacitance with the transformer ratio-arm bridge circuit was checked by replacing it by one based on a capacitive divider system, as used by others (9), (12), (16) for measuring capacitance of main bearings. Both methods yielded essentially the same capacitancelcrankangle and h,Icrankangle curves for a given oil.…”

Section: Test Precisionmentioning

confidence: 99%

Oil Film Thickness in an Elastic Connecting-Rod Bearing: Comparison Between Theory and Experiment

Bates

Fantino

Launay

et al. 1990

Tribology Transactions

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Tile minim~~m oil film thickness in a dynamically loaded cone n d bearing of a high-speed, fuel injected, 2.8 litre, V-6 nec1ivt.g-ro(1, big-end bearing of a /ti$-speed gasoline engine has (60") gasoline engine; bore a n d stroke were 93 r~~m and been studied experimenlolly and tkeoretically. The theoretical cal-68.5 mm whilst was 9.2:1; c~~l r~t i o~~ were cc~rried outfir bolh rigid and elastic bearings. The the engine had a brake l o kW a t 5800 rlmin and a maximum torque o f 216 N.m at 4000 rheoly k (~Lso w~ed to explore the effects on the experimental results rlmin; the crankshaft had four main bearings. ($ (L it~echnnicnl scissor linkage and of l/te assumption that there isT h e big-end bearing shells were ungrooved, their dino rli.slorlion or cavilntioit. Coinpanions are made between the ameter a n d width being 54.0 m m a n d 16.5 m m respectively. llreory I L I I (~ ex/)e?Zment of the effects of cranksitaft speed and lu-The bearing material was copperllead on a steel backing bricc~nt visco.sily.with a ca. 10 p m thick leadltin overlay; the total thickness of the shell was 1.4 mm. Oil was fed to the bearing via a -

show abstract

A Comparison of the Total Capacitance and Total Resistance Techniques for Measuring the Thickness of Journal Bearing Oil Films in an Operating Engine

Cited by 26 publications

References 8 publications

Comparison between Theoretical Calculations and Oil Film Thickness Measurements Using the Total Capacitance Method for Crankshaft Bearings in a Firing Engine

Comparison between Theoretical Calculations and Oil Film Thickness Measurements Using the Total Capacitance Method for Crankshaft Bearings in a Firing Engine

Fuel economy in heavy duty diesel engines. Part 1: measurement of oil film thickness on an operating engine

Oil Film Thickness in an Elastic Connecting-Rod Bearing: Comparison Between Theory and Experiment

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