SOME ASPECTS OF INFLUENCE OF THE CONNECTING ROD DESIGN ON THE OUTPUT PARAMETERS OF HIGH-SPEED INTERNAL  COMBUSTION ENGINES

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.

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Nonlinear Transient Response of a High Speed Driven Valve System and Stresses in Valve Springs for Internal Combustion Engines

Journal of Vibration and Acoustics ◽

10.1115/1.3269851 ◽

1989 ◽

Vol 111 (3) ◽

pp. 264-271 ◽

Cited By ~ 2

Author(s):

K. Nagaya

Keyword(s):

High Speed ◽

Internal Combustion Engines ◽

Three Dimensional ◽

Beam Theory ◽

Internal Combustion ◽

Valve Train ◽

Combination Method ◽

Combustion Engines ◽

Valve System ◽

Cam Profile

This paper presents a method for solving the dynamic response problems of a driven valve system and the stress problem of valve springs for internal combustion engines. In this system there is hysteresis behavior in the spring constants during the rotation of the cam shaft. To treat this nonlinearity, the rigidity of each section is assumed to be one of a partly linear spring. For the valve trains, the cam profile is complex in general. To treat a general cam profile, this paper applies a combination method of the Fourier expansion, the Laplace transform and the analytical connection methods, and gives a response of valve trains. This paper also presents a theoretical result for the stresses in the valve spring due to the motion of the valve train based on the three dimensional curved beam theory.

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High-speed Internal-combustion Engines

Nature ◽

10.1038/099124a0 ◽

1917 ◽

Vol 99 (2476) ◽

pp. 124-124

Keyword(s):

High Speed ◽

Internal Combustion Engines ◽

Internal Combustion ◽

Combustion Engines

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A zonal approach for estimating pressure ratio at compressor extreme off-design conditions

International Journal of Engine Research ◽

10.1177/1468087418754899 ◽

2018 ◽

Vol 20 (4) ◽

pp. 393-404 ◽

Cited By ~ 8

Author(s):

José Galindo ◽

Roberto Navarro ◽

Luis Miguel García-Cuevas ◽

Daniel Tarí ◽

Hadi Tartoussi ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

High Speed ◽

Internal Combustion Engines ◽

Pressure Ratio ◽

Internal Combustion ◽

Operating Conditions ◽

Combustion Engines ◽

One Dimensional ◽

Performance Map

Zero-dimensional/one-dimensional computational fluid dynamics codes are used to simulate the performance of complete internal combustion engines. In such codes, the operation of a turbocharger compressor is usually addressed employing its performance map. However, simulation of engine transients may drive the compressor to work at operating conditions outside the region provided by the manufacturer map. Therefore, a method is required to extrapolate the performance map to extended off-design conditions. This work examines several extrapolating methods at the different off-design regions, namely, low-pressure ratio zone, low-speed zone and high-speed zone. The accuracy of the methods is assessed with the aid of compressor extreme off-design measurements. In this way, the best method is selected for each region and the manufacturer map is used in design conditions, resulting in a zonal extrapolating approach aiming to preserve accuracy. The transitions between extrapolated zones are corrected, avoiding discontinuities and instabilities.

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