Study of the Piston Secondary Movement on the Tribological Performance of a Single Cylinder Low-Displacement Diesel Engine

The present study aims to analyze the secondary movement of the piston considering the deformations present in the piston skirt, the hydrodynamic lubrication, and the effects of the clearances in the connecting rod bearings. The analysis of the piston movement is performed by developing a mathematical model, which was used to evaluate the dynamic characteristics of the piston movement, the slap force on the piston skirt, the effect of the secondary piston movement on the connecting rod, and the influence of clearances in the connecting rod bearings and in the piston. For the study, the geometric of the crankshaft-connecting rod–piston system of a single-cylinder diesel engine is taken as a reference. The deformation model of the piston was carried out by means of a symmetric finite element model (FEM), which was integrated into the mathematical model of the piston. MATLAB® software (The MathWorks Inc., Natick, MA, USA) is used for the development of model simulations. The obtained results show that during the combustion cycle, there are six changes of direction in the secondary movement of the piston with lateral and angular velocities that can reach a magnitude of 0.13 m/s and 4 rad/s. The lateral and angular movement of the piston during its travel causes the appearance of impacts on the piston skirt with the cylinder liner, which produces an increase of approximately 500 N in the hydrodynamic forces in the connecting rod bearings. The force analysis shows that the range of the maximum magnitudes of these forces is between 1900 N and 3480 N. The increase in clearance between the cylinder liner and the piston skirt (Cpc) causes a greater lateral displacement and an increase in the angle of inclination of the piston. Analysis of the change in connecting rod bearing clearance shows that there are critical values in relation to clearance Cpc. The model presented allows us to analyze the different characteristics of the secondary movement of the piston, which involve the interaction between the piston skirt and the cylinder liner. Additionally, the influence of this movement on the connecting rod bearings is considered. The foregoing can be used as an analysis tool for the study of designs and/or modifications in the engine in such a way that greater durability of the components, reductions in acoustic emissions, and reduction in friction losses are achieved.

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Comparative Evaluation of Fatigue Assessment Techniques on a Forged Steel Crankshaft of a Single Cylinder Diesel Engine

Volume 3: Design, Materials and Manufacturing, Parts A, B, and C ◽

10.1115/imece2012-85493 ◽

2012 ◽

Author(s):

Rajesh M. Metkar ◽

Vivek K. Sunnapwar ◽

Subhash Deo Hiwase

Keyword(s):

Diesel Engine ◽

Fracture Mechanics ◽

Early Stage ◽

Life Assessment ◽

Growth Time ◽

Connecting Rod ◽

Rotating System ◽

Element Analysis ◽

Ic Engine ◽

Single Cylinder

Crankshaft is one of the critical components of an IC engine, failure of which may result in disaster and makes engine useless unless costly repair performed. It possesses intricate geometry and while operation experiences complex loading pattern. In IC engines, the transient load of cylinder gas pressure is transmitted to crankshaft through connecting rod, which is dynamic in nature with respect to magnitude and direction. However, the piston along with connecting rod and crankshaft illustrate respective reciprocating and rotating system of components. the dynamic load and rotating system exerts repeated bending and shear stress due to torsion, which are common stresses acting on crankshaft and mostly responsible for crankshaft fatigue failure. Hence, fatigue strength and life assessment plays an important role in crankshaft development considering its safety and reliable operation. The present paper is based on comparative studies of two methods of fatigue life assessment of a single cylinder diesel engine crankshaft by using fracture mechanics approach viz. linear elastic fracture mechanics (LEFM) and recently developed critical distance approach (CDA). These methods predict crack growth, time required for failure and other parameters essential in life assessment. LEFM is an analytical method based on stress intensity factor which characteristics the stress distribution in the vicinity of crack tip, where as CDA is a group of methods predicts failure using stress distance plot. The maximum stress value required for both the methods are obtained using finite element analysis. The present paper provides an insight of LEFM and CDA methods along with its benefits to the designers to correctly assess the life of crankshaft at early stage of design. This paper also gives a detailed overview of failure analysis process including theoretical methods and result integration for predicting life of components as compared to life estimation by means of software.

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The Analysis of Secondary Motion and Lubrication Performance of Piston considering the Piston Skirt Profile

Shock and Vibration ◽

10.1155/2018/3240469 ◽

2018 ◽

Vol 2018 ◽

pp. 1-27 ◽

Cited By ~ 3

Author(s):

Yanjun Lu ◽

Sha Li ◽

Peng Wang ◽

Cheng Liu ◽

Yongfang Zhang ◽

...

Keyword(s):

Thermal Deformation ◽

Work Performance ◽

Cylinder Liner ◽

Connecting Rod ◽

Piston Skirt ◽

Piston Cylinder ◽

Lubrication Performance ◽

Rod System ◽

Liner System ◽

Secondary Motion

The work performance of piston-cylinder liner system is affected by the lubrication condition and the secondary motion of the piston. Therefore, more and more attention has been paid to the secondary motion and lubrication of the piston. In this paper, the Jakobson-Floberg-Olsson (JFO) boundary condition is employed to describe the rupture and reformation of oil film. The average Reynolds equation of skirt lubrication is solved by the finite difference method (FDM). The secondary motion of piston-connecting rod system is modeled; the trajectory of the piston is calculated by the Runge-Kutta method. By considering the inertia of the connecting rod, the influence of the longitudinal and horizontal profiles of piston skirt, the offset of the piston pin, and the thermal deformation on the secondary motion and lubrication performance is investigated. The parabolic longitudinal profile, the smaller top radial reduction and ellipticities of the middle-convex piston, and the bigger bottom radial reduction and ellipticities can effectively reduce the secondary displacement and velocity, the skirt thrust, friction, and the friction power loss. The results show that the connecting rod inertia, piston skirt profile, and thermal deformation have important influence on secondary motion and lubrication performance of the piston.

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Dynamic Analysis of the Crank Train in a Single Cylinder Diesel Engine Using a Lumped Parameter Method

ASME 2016 Internal Combustion Engine Fall Technical Conference ◽

10.1115/icef2016-9337 ◽

2016 ◽

Author(s):

X. Y. Zhang ◽

J. Guo ◽

Zhang Wenping

Keyword(s):

Diesel Engine ◽

Dynamic Analysis ◽

Internal Force ◽

Parameter Method ◽

Cylinder Pressure ◽

Connecting Rod ◽

Single Cylinder ◽

Rotating Speed ◽

Lumped Parameter ◽

Lumped Parameter Method

The kinematic and dynamic behaviors of the crank train in a single cylinder diesel engine are analyzed in the paper. The crank train mechanism consists of four parts: a crank without counterweight, a connecting rod, a piston associated with a cylinder and two stops at both ends of a stroke. The dynamic model is developed using a lumped parameter method. The inertia of mass or moment are considered by an equivalent treatment in the centers of the piston pin, the crank pin, the main journal, respectively. The longitudinal deformations of the connecting rod are simulated by spring-damping elements, as well as the angular and bending deformations of the crank. As a result, it was possible to predict the effects of the component inertia of mass or moment and stiffness on the internal force and rotating speed of the crank under the cylinder pressure.

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Vibration Analysis of a Single-Cylinder Reciprocating Compressor considering the Coupling Effects of Torsional Vibration

Shock and Vibration ◽

10.1155/2019/3904595 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Siyuan Liu ◽

Wanyou Li ◽

Zhijun Shuai ◽

Meilong Chen

Keyword(s):

Torsional Vibration ◽

Vibration Analysis ◽

Transfer Functions ◽

Cylinder Liner ◽

Angular Speed ◽

Reciprocating Compressor ◽

Connecting Rod ◽

Single Cylinder ◽

Rotating Speed ◽

Instantaneous Angular Speed

A piston slap is one of the main vibration sources of the reciprocating machinery. Much work has been done in this field, most of which was based on a constant rotating speed. However, in practice, the speed of a crankshaft may always fluctuate due to the uneven load or excitation. The inertia forces of moving components are much different at the fluctuating rotating speed comparing with that at a constant speed. In this paper, the piston slap and the induced vibration are analyzed based on the instantaneous angular speed measured on a single-cylinder reciprocating compressor. Firstly, the dynamics of a crank-connecting rod mechanism is analyzed based on the measured instantaneous angular speed which contains the torsional vibration of the air compressor. The time histories of piston slap impact forces considering and without considering torsional vibration are compared. Then, in order to correlate the piston slap impact with the slap-induced vibration, the corresponding transfer functions between the middle stroke of the outer surface of the cylinder liner and the excitation points are measured. And the excitation force on the main bearing is also taken into account to bring the simulation closer to the experimental results. The effects of a torsional vibration on the vibration of the cylinder liner are analyzed, and the simulation results show that the torsional vibration is a factor that must be taken into account in the vibration analysis of the single-cylinder reciprocating compressor.

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ASSESSMENT OF THE INFLUENCE OF MICROTEXTURING PARAMETERS ON THE HYDROMECHANICAL CHARACTERISTICS OF DIESEL CRANKSHAFT BEARINGS

Bulletin of the South Ural State University series Mechanical Engineering Industry ◽

10.14529/engin200104 ◽

2020 ◽

Vol 20 (1) ◽

pp. 30-37

Author(s):

Yu. V. Rozhdestvensky ◽

◽

K. V. Gavrilov ◽

M. A. Izzatulloev ◽

◽

...

Keyword(s):

Diesel Engine ◽

Internal Combustion Engine ◽

Combustion Engine ◽

Cylinder Liner ◽

Internal Combustion ◽

Calculation Model ◽

Operating Conditions ◽

Energy Losses ◽

Connecting Rod ◽

Friction Regime

The solution to the problem of increasing the motor resource of an internal combustion engine (ICE) is directly related to the reduction of energy losses due to overcoming friction in the elements of systems, mechanisms, and complexly loaded tribo-couplers (TC). Among the mechanical friction losses, a special place isoccupied by the hydromechanical friction losses in the internal combustion engine. The reduction of energy losses to overcome friction is achieved by reducing mechanical losses by limiting the level of loading of the rubbing surfaces, by increasing the proportion of the liquid friction regime for the most critical in terms of reliability resource-determining complex loaded vehicles. For complexly loaded vehicles, the time and magnitude of the acting loads are characteristic, at which the position of the movable element in conjunction is characterized by high eccentricities. Such complexly loaded vehicles include the main and connecting rod bearings of the crankshaft, the “piston guide – cylinder liner” and “piston ring – cylinder liner” couplings, the thrust and thrust bearings of the ICE turbocharger, etc. One of the ways to reduce oil starvation isto texturize the contacting surfaces, which will increase the bearing capacity of a complex bearing due to the creation of many “micro wedges”. In particular, the texturing of the surface of the bearing shells of the crankshaft can be performed in the form of elliptical micro-holes, which allow you to save oil on the friction surface under any operating conditions of the diesel engine. The article provides an overview of the main types of microtexturing of friction surfaces of TC. A calculation model has been created and a calculation analysis program has been developed for the internal combustion engine “crankshaft neck-liner” TC. The calculations ofthe hydromechanical characteristics (HMC) of the vehicle for various types of microtexture were performed using the connecting rod bearing of the diesel engine CHN 13/15 as an example.

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Finite Element Strength Analysis on 12V280 Diesel Engine Connecting Rod

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.889-890.179 ◽

2014 ◽

Vol 889-890 ◽

pp. 179-186

Author(s):

Ming Hai Li ◽

Lei Ni

Keyword(s):

Finite Element ◽

Diesel Engine ◽

Strength Analysis ◽

Analysis Tool ◽

The Finite Element Method ◽

Connecting Rod ◽

Ansys Software ◽

Element Analysis ◽

Main Research ◽

Reliable Basis

Taking a certain type of diesel engine connecting rod as the research object and the finite element method as the main research means.This paper uses PROE software for solid modeling tool and ANSYS software for finite element analysis tool,Static analysis is carried out on the connecting rod. Analyze connecting rod under different conditions of stress distribution and dangerous parts. This paper provides the reliable basis for the design and improvement of connecting rod.

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The Novel Design of Full-Balancing Mechanism for Single-Cylinder Diesel Engine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.1520 ◽

2010 ◽

Vol 37-38 ◽

pp. 1520-1524

Author(s):

Bi Feng Yin ◽

Jiang Guang He ◽

Yi Xu ◽

Yong Qiang Li

Keyword(s):

Diesel Engine ◽

Inertia Force ◽

The Novel ◽

Connecting Rod ◽

Single Cylinder ◽

Piston Group ◽

Engine Piston ◽

Groove Guide ◽

Inertia Forces ◽

Novel Design

One new sliding-block balancing mechanism is proposed for the single-cylinder diesel engine. In the new mechanism, the sliding block is installed against the engine piston. The reciprocation trajectory of sliding block is collinear with the piston trajectory, while sliding block and piston move in the opposite direction, just like two opposite crank connecting rods. The new mechanism includes the crankshaft, connecting rod ring, the slider and the guide components. Through the bearing, connecting rod is installed in the eccentric journal of the crankshaft. The circular connecting rod is in the accurate guiding surface of the slider; and the guide pins are in the guide groove. Guide rod connects with supporting shaft through the guide hole of the slide. The optimized parameters for the sliding block show that the ratio of eccentric distance of the eccentric journal to the length of the connecting rod is equal to the ratio of crank radius to connecting rod length. The appropriate results can balance both the centrifugal inertia force and the reciprocating inertia force generated by piston group. Even the complete balance of the first and second-order reciprocating inertia forces can be obtained, which can reduce the vibration and noise of diesel engine.

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Investigation of different piston ring curvatures on lubricant transport along cylinder liner in large two-stroke marine diesel engines

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650117744100 ◽

2017 ◽

Vol 232 (1) ◽

pp. 85-93 ◽

Cited By ~ 4

Author(s):

H Overgaard ◽

P Klit ◽

A Vølund

Keyword(s):

Diesel Engine ◽

Piston Ring ◽

Reynolds Equation ◽

Hydrodynamic Lubrication ◽

Cylinder Liner ◽

Marine Diesel Engine ◽

Cyclic Variation ◽

Ring Shape ◽

Marine Diesel ◽

The Finite Difference Method

A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect of changes in radii is analysed. A numerical model based on the finite difference method in 1D has been developed for solving Reynolds equation in combination with the load equilibrium equation together with flow continuity between the piston ring surface and liner for analysis of the lubricant transport. The cyclic variation throughout one stroke is presented for the minimum film thicknesses at different interesting locations of the piston ring surface together with the friction and the pressure distribution history. The aforementioned parameters have been investigated numerically. The numerical results are presented and discussed.

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Prediction of Nonlinear Contact Force of Piston Skirt and Cylinder Liner under the Function of Clap Force

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.831 ◽

2012 ◽

Vol 226-228 ◽

pp. 831-834

Author(s):

Zhou Jin ◽

Zhi Zhuang Yu ◽

Lin Sheng Yang

Keyword(s):

Contact Stress ◽

Working Condition ◽

Hydrodynamic Lubrication ◽

Cylinder Liner ◽

Contact Model ◽

Piston Skirt ◽

Nonlinear Contact ◽

Hydrodynamic Lubrication Theory ◽

Stress And Deformation ◽

Dangerous Condition

The piston skirt and cylinder liner is a coupled contact model, It is of great importance to analyze the contact stress and deformation. Due to the existence of the gap and the lateral clap force between piston skirt and cylinder liner, which leads to the lateral movement. According to the secondary movement and hydrodynamic lubrication theory, the maximum lateral clap force can be obtained in a working condition, before piston crosses TDC, the huge gas pressure makes the piston skirt and cylinder liner collision contact, and creates the enormous clap force, which can aggravate the noise and vibration between piston skirt and cylinder liner. We would set maximum lateral clap force as a dangerous condition, which can be loaded on the contact model. By the means of nonlinear software ABAQUS, to establish the piston skirt and cylinder liner contact model, and analyze the contact stress and deformation.

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