scholarly journals Analysis of balancing of six-cylinder in-line two-stroke internal combustion engines

2009 ◽  
Vol 139 (4) ◽  
pp. 22-33
Author(s):  
Ryszard MOSAKOWSKI
Keyword(s):  
Comparative Analysis ◽  
Internal Combustion Engines ◽  
Second Order ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Moments Of Inertia ◽  
First Order ◽  
L Value ◽  
The Moment ◽  
Inertia Forces

Simple relations describing the resultant moments of inertia forces of the first and second order for all sixty possible configurations of the crankshaft in two-stroke four-cylinder engine have been derived in the paper. A comparative analysis of the crankshafts with different arrangements of cranks have been carried out with respect to the resultant moments of the first and second order inertia forces. The comparison has been carried out for two values of the crank throw to connecting rod length ratio, namely l = 0.3 and l = 0.5. The outcomes of the comparative analysis indicate that irrespective of the l value, within the range of its values having practical meanings, the arrangement of cranks 1-5-3-4-2-6 is the best. As a result of 50% balancing of the moment of the first order inertia forces the differences between various configurations of the crankshaft are significantly reduced and configuration 1-4-2-6-3-5 equals with respect to balancing with the commonly used configuration 1-5-3-4-2-6.

scholarly journals Analysis of balancing of four stroke V6 engines

2013 ◽  
Vol 155 (4) ◽  
pp. 44-55
Author(s):  
Ryszard MOSAKOWSKI
Keyword(s):  
Moment Of Inertia ◽  
Reciprocating Motion ◽  
Connecting Rod ◽  
Bank Angle ◽  
First Order ◽  
Cylinder Bank ◽  
The Moment ◽  
Inertia Forces ◽  
Selection Of

Analysis of balance of V6 engines with a common-pin crankshaft depending on a cylinder bank angle and the crank radius to connecting rod length ratios l based on the relations derived is presented in the paper. The bank angles providing the lowest moment of inertia forces in reciprocating motion for selected l values were determined. The position of the plane of the main counterweights in order to maximum balance of the moment of the first order inertia forces and degree of its balancing in the function of the cylinder bank angle were also defined in the paper. The position of the balancing shaft with respect to the crankshaft to fully balance the moments of the first order inertia forces was also determined. Apart from the quality of balancing, also other criteria for the selection of the cylinder bank angle of vehicle engines were indicated in the paper.

scholarly journals A Novel Coaxial Balance Mechanism for Reciprocating Piston Engines

2021 ◽  
Vol 11 (12) ◽  
pp. 5647
Author(s):  
Nanxiang Guan ◽  
Ao Wang ◽  
Yongpeng Gu ◽  
Zhifeng Xie ◽  
Ming Zhou
Keyword(s):  
Reaction Force ◽  
Vibration Reduction ◽  
Second Order ◽  
Root Mean Square Velocity ◽  
First Order ◽  
Support Reaction ◽  
Cylinder Piston ◽  
Test Points ◽  
Balance Mechanism ◽  
Inertia Forces

Vibration is an important issue faced by reciprocating piston engines, and is caused by reciprocating inertia forces of the piston set. To reduce the vibration without changing the main structure and size of the original engine, we proposed a novel coaxial balance mechanism design based on a compact unit body. By introducing a second-order balance mass, this mechanism can significantly increase the efficiency of vibration reduction. The proposed mechanism can effectively balance the first-order and second-order inertia forces with the potential of balancing high-order inertia forces. To accurately determine the second-order balance mass, a closed-form method was developed. Simulation results with a single-cylinder piston DK32 engine demonstrate the effectiveness and advantage of the proposed mechanism. At a crankshaft speed of 2350 r/min, compared with the first-order balance device, the average root mean square velocity of the test points on the engine’s cylinder was reduced by 97.31%, and the support reaction force was reduced by 96.54%.

A Probabilistic Approach to Engine Balance

1999 ◽  
Vol 122 (4) ◽  
pp. 526-532 ◽  
Author(s):  
Dinu Taraza
Keyword(s):  
Internal Combustion Engines ◽  
Probabilistic Approach ◽  
Rayleigh Distribution ◽  
Statistical Characteristics ◽  
Balance Model ◽  
Combustion Engines ◽  
Normal Distributions ◽  
First Order ◽  
Rayleigh Law ◽  
Manufacturing Tolerances

The paper presents an original probabilistic model of the balance of internal combustion engines. The model considers the manufacturing tolerances and predicts the most probable value of the first-order residual unbalance for engines that—theoretically—have the first order forces and moments balanced. It has been found that, assuming normal distributions of the geometric and mass parameters of the reciprocating mechanisms of a multicylinder engine, the unbalancing forces and moments are statistically distributed according to a Rayleigh law. The mode of the Rayleigh distribution, which represents the most probable value of the residual unbalance, is expressed in terms of the statistical characteristics of the parameters subjected to manufacturing tolerances. In this way, the tolerances and, especially the ones admitted for the reciprocating masses, are directly correlated to the expected value of the residual unbalance making it possible to establish reasonable limits for these tolerances. Validation of the probabilistic balance model is demonstrated by computer simulation. [S0742-4795(00)01704-X]

scholarly journals The influence of centrial forces on crankshaft bearing lubrication is in emergency modes of the engine of the car

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Operating Mode ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Oil Supply ◽  
Technical Expert ◽  
The Difference

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.

scholarly journals Comparative analysis of balancing of V6 engines with common- and split-pin crankshafts

2014 ◽  
Vol 156 (1) ◽  
pp. 3-12
Author(s):  
Ryszard MOSAKOWSKI
Keyword(s):  
Comparative Analysis ◽  
Point Of View ◽  
Reciprocating Motion ◽  
Bank Angle ◽  
Moments Of Inertia ◽  
Cylinder Bank ◽  
Mathematical Relation ◽  
Inertia Forces ◽  
Mathematical Relations

An analysis of balancing of V6 engines equipped with split-pin crankshafts with any cylinder bank angle based on the mathematical relations derived in the paper was carried out. A comparison of the quality of their balancing with engines equipped with common-pin crankshafts was also carried out. The bank angle ranges beneficial for balancing of moments of inertia forces in reciprocating motion were determined. A mathematical relation on the optimum value of the main counterweights in the function of the cylinder bank angle was derived as well. The advantages of the split-pin crankshafts from the point of view of balancing were also indicated also.

scholarly journals Hydrogen resistance to knock combustion in spark ignition internal combustion engines

2011 ◽  
Vol 144 (1) ◽  
pp. 13-19
Author(s):  
Stanisław SZWAJA
Keyword(s):  
Compression Ratio ◽  
Internal Combustion Engines ◽  
Spark Ignition ◽  
Combustion Engines ◽  
Pressure Pulsations ◽  
Combustion Analysis ◽  
Dual Nature ◽  
The Moment ◽  
High Pass ◽  
Hydrogen Resistance

The results of investigations focusing on knock combustion analysis of a hydrogen-fueled engine have been presented in the paper. Knock intensity was determined as the intensity of the in-cylinder combustion pressure pulsations (recorded with a sampling frequency of 100 kHz) and filtered through high-pass filtering with cut-off frequency of 3.5 kHz. The research was conducted on the CFR engine with a variable compression ratio ranging from 6 to 14. The research has shown a rapid increase in pressure pulsations amplitude was observed while the compression ratio was changed from 11 to 12. This was interpreted as a result of in-cylinder hydrogen-air mixture self-ignition at the end of the spark ignition controlled combustion. Supporting this observation the theorem of dual nature of hydrogen knock combustion was postulated. Intensity of the pressure pulsations that accompany normal combustion without hydrogen self-ignition was in an exponential correlation with the compression ratio, which directly translates into a similar correlation of the pulsations and temperature of hydrogen-air mixture at the moment of ignition.

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