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The free piston linear engine (FPLE) eliminates the crankshaft components and supports variable compression ratio operation. This characteristic makes it as one of the most appropriate choices to adopt HCCI combustion mode. This work aims to reveal the preliminary characteristics of HCCI combustion in FPLE and compare it with traditional crankshaft engines (TCE). The HCCI combustion model of TCE and FPLE was established by using a chemical kinetic reaction mechanism, and it then was numerically calculated to obtain the combustion and emission performance. The results indicate that the typical two-stage reaction characteristic of HCCI combustion also occur in the FPLE. Although the final cumulative heat release of the two types of engines is approximately the same, the low-temperature reaction stage of FPLE comes later, which also leads to the lag of its high-temperature reaction stage. In addition, the TCE features with earlier heat release rate, higher peak pressure and temperature, and longer duration of high temperature, which are beneficial to promote the reaction of soot, thereby slightly reducing soot emissions, but also increasing NO emissions.

This article describes one of the possible ways for improving the energy efficiency of shunting diesel locomotives. It means a replacing a traditional traction electric transmission with a diesel generator set with a hybrid transmission with a free-piston internal combustion engine and a linear generator. The absence of a crankshaft in an internal combustion engine makes it possible to reduce thermal and mechanical losses, which, in turn, leads to an increase in the efficiency of traction electric transmission of the diesel locomotive.

Torsional vibration (TV) is one of the major issues and very important calculation for the safe running of internal combustion engines, specifically crankshaft. The properties of parts connected to the crankshaft have significant effect on vibration of the system as well as the crankshaft life. Initial selection of this part is usually specified based on engine designer experience and also the torsional vibration calculation of the crank train. In this paper, the focus is to find optimum tuned mass to connect to the crankshaft from the damper side using CAE tools. It is a mounting disk at the free end of the crankshaft named tuned mass. Therefore, the effect of tuned mass inertia on design criteria, especially crankshaft life, was investigated. The results show high sensitivity of high cycle fatigue safety factor of crankshaft to tuned mass. Therefore, adding a suitable tuned mass to the system can increase the crankshaft life, when needed. The results were presented in the paper in detail

Automotive industry is migrating to electronic based control which has promoted the evaluation and enhancement of engine control performance using electronic components in the research field. Modern engines are controlled by Engine Control Unit (ECU) where not only functions and control systems are in placed, but also the fail-safe mechanisms must be integrated in the ECU to ensure user safety when an error occurred. This work focuses on developing a reliable crankshaft function in an ECU using field-programmable gate array (FPGA). ABa test is carried out and the number of occurrences at unintended location are being monitored in the system to detect the random missing tooth. The reliability of the function is tested by evaluating response of the crankshaft function in an ECU when an unexpected missing tooth occurs during its operation. The developed system is able to detect the random missing tooth on a crank trigger wheel at an accuracy of 100% when the wheel is on a run at a constant wheel rotational speed. It also flags error message for further processing in other functional units of the ECU as a safe-fail mechanism for the system. Implementation of the random missing tooth detection in the crankshaft function is shown to work in the system which is developed using Verilog code

PurposeThe purpose of this paper is to study the fault diagnosis of internal combustion (IC) engine gearbox using vibration signals with signal processing and machine learning (ML) techniques.Design/methodology/approachVibration signals from the gearbox are acquired for healthy and induced faulty conditions of the gear. In this study, 50% tooth fault and 100% tooth fault are chosen as gear faults in the driver gear. The acquired signals are processed and analyzed using signal processing and ML techniques.FindingsThe obtained results show that variation in the amplitude of the crankshaft rotational frequency (CRF) and gear mesh frequency (GMF) for different conditions of the gearbox with various load conditions. ML techniques were also employed in developing the fault diagnosis system using statistical features. J48 decision tree provides better classification accuracy about 85.1852% in identifying gearbox conditions.Practical implicationsThe proposed approach can be used effectively for fault diagnosis of IC engine gearbox. Spectrum and continuous wavelet transform (CWT) provide better information about gear fault conditions using time–frequency characteristics.Originality/valueIn this paper, experiments are conducted on real-time running condition of IC engine gearbox while considering combustion. Eddy current dynamometer is attached to output shaft of the engine for applying load. Spectrum, cepstrum, short-time Fourier transform (STFT) and wavelet analysis are performed. Spectrum, cepstrum and CWT provide better information about gear fault conditions using time–frequency characteristics. ML techniques were used in analyzing classification accuracy of the experimental data to detect the gearbox conditions using various classifiers. Hence, these techniques can be used for detection of faults in the IC engine gearbox and other reciprocating/rotating machineries.

Noise, vibration, and harshness (NVH) simulators enable the subjective evaluation of vehicle interior noise and improvement of the NVH performance. To achieve a powerful and sporty engine sound, several original equipment manufacturers of automobile parts introduce the engine intake noise into the vehicle cabin through pipe systems that reinforce the low-frequency engine noise components. The present study proposes an intake-noise module that simulates an intake-noise reinforcing system and can be integrated with the previously developed NVH simulator. The intake- noise simulation module is based on the intake noise source model, pipe system model, and room impulse response model. The pipe system is modeled by the transfer-matrix method (TMM), and the room impulse response is modeled using the image-source method. The intake noise source is time variant because the noise source depends on the rotational speed of the engine and the crankshaft angle. TMM is also time variant because the noise propagation characteristics in TMM vary with the throttle valve angle. Intake noise source and TMM are designed in the frequency domain. In two cases of intake-noise reinforcing system, the loudness and sharpness (which are known to be correlated with a sporty engine noise) are calculated for the simulated data. The developed NVH simulator can assist the design of intake-noise reinforcing systems that reach the targeted sound quality.

The paper analyzes the deformation of the connecting rod stem with buckling due to water ingress into the internal combustion engine cylinder (the so-called hydrolock). A method is presented that has been developed to perform calculations of stem deformation in the process of compressing air with liquid in an internal combustion engine cylinder. The method is based on solving a system of differential equations for pressure and temperature in the cylinder, followed by calculating the compression force acting on the connecting rod. A carried-out simulation of the compression process demonstrates the dependence of the air pressure in the cylinder, the stress and the strain of the connecting rod on the fill ratio of the combustion chamber with liquid. The calculations performed according to the classical theory of resistance of materials have shown that the connecting rod with the buckling of the stem begins to deform when the liquid fills the combustion chamber to a minimum of 80%. With the increase in the amount of liquid, the deformation of the conrod increases, and when the level of liquid filling is so significant that it exceeds the volume of the combustion chamber, the conrod stem deformation reaches extreme values. It is shown that under these conditions after the hydrolock occurs the engine may fail due to the piston wedging the crankshaft in the bottom dead center position.

The use of roller bearings as crankshaft main bearings has shown potential in reducing the fuel consumption of internal combustion engines. An effective way to mount the roller bearing onto the crankshaft is to split the outer ring. However, this may lead to a severe out-of-roundness in the split region when the bearing is mounted, further implying increased noise, vibrations and contact stresses. In this work, a novel approach to study the plasto-elastohydrodynamic contact using commercial finite element software is developed. The modelling approach is based on the contact moving in space, allowing for the stress history based on the lubricant pressure to be studied in a straight-forward manner. The model is first utilised to study the influence of asperities on the lubricating conditions, indicating that stresses may exceed the yield strength of the material due to the transient effects taking place when the surface feature is over-rolled. Thereafter, the model is used to analyse the step in a mounted crankshaft roller bearing with the purpose of specifying a critical step height, which implies zero plasticity and thereby a reduced risk of accumulated damage in the vicinity of the step.

The dual mass flywheel especially used in diesel engines has a structure in which the single- mass flywheel is divided into two parts and these two parts are combined with a curved helical spring. The flywheel is a part that reduces the speed fluctuations in the crankshaft of the internal combustion engines. In addition to this function, the dual mass flywheel dampens the torsional vibrations better than the clutch disc springs thanks to the spring system found in its structure. There are no torsional springs in the disc of the clutch system where dual mass flywheel is used. The dual mass flywheel is used with a rigid clutch disc without torsion springs. From this point of view, it is thought that the clutch dynamics of both systems are different. For this purpose, mathematical models of both systems were formed. The obtained models were solved after the appropriate transformations. As a result, it was seen the clutch engagement times are almost same in both systems. However in the clutch system where the dual mass flywheel is used the clutching process is performed more smoothly.

Purpose This paper aims to numerically investigate the surface texturing effects on the main bearings of a three-cylinder ethanol engine in terms of the power loss and friction coefficient for dynamic load conditions. Design/methodology/approach The mathematical formulation considers the Partir-Cheng modified Reynolds equation. The mass-conserving Elrod-Adams p-θ model with the JFO approach is used to deal with cavitation. A fluid-structure coupling procedure is considered for the elastohydrodynamic lubrication. Accordingly, a 3-D linear-elastic substructured finite element model obtained from Abaqus is applied Findings Simulations were carried out considering different dimple texture designs in terms of location, depth and radius. The results suggested that there are regions where texturing is more effective. In addition, distinct journal rotation speeds are studied and the surface texture was able to reduce friction and the power loss by 7%. Practical implications The surface texturing can be a useful technique to reduce the power loss on the crankshaft bearing increasing the overall engine efficiency. Originality/value The surface texturing performance in a three-cylinder engine using ethanol as fuel was investigated through numerical experimentation. The results are supported by previous findings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2019-0380/

Oscillating grinding machine tool is the core equipment when machining crankshaft pin journal, which directly determines the final quality. This paper describes the development of an oscillating grinding machine tool based on error analysis. First, the error analysis of oscillating grinding for crankshaft pin journal is carried out, including the effect on machining accuracy caused by each error and corresponding error sensitivity. The results show that the tracking error of X-axis has the greatest influence on the grinding accuracy of pin journal, thus, the grinding carriage feed system is the critical component of an oscillating grinding machine tool, which should be given priority during the development process. Next, the development of an oscillating grinding machine tool is described. The whole structure is given, and the grinding carriage feed system is emphatically presented involving drive mode and assembly method. Other components of the oscillating grinding machine tool are also introduced. Finally, some grinding experiments are performed on the prototype, and the results show that all workpieces are qualified under different conditions, which verify the performance of the developed oscillating grinding machine tool.

The article contains an analysis of thermodynamic indicators of the CI engine with direct fuel injection. The tested unit was an engine with an unconventional crank-piston configuration, in which at a constant compression ratio, different engine crankshaft control variants were compared. In this article the time ranges in which the piston was located in the TDC were analyzed. Additionally, tests were carried out on a conventional unit for comparative purposes. For the purposes of the work, a piston displacement characteristic was generated in dynamic analysis in SolidWorks Motion. Then, this characteristic was used in the simulations of the combustion process in the AVL Fire program, where the most important thermodynamic indicators of the engine cycle were analyzed.

The crankshaft is one of the most important loaded components in the engine, as it is experiencing cyclic loads in the form of a bending and torsion. In the study, crankshaft of the single-cylinder engine and crankshaft of the four-cylinder engine were designed in the SOLID WORKS software. Then these designs were transferred to ANSYS software with finite element method. Both crankshafts were compared in terms of stress and deformation. Critical areas had been identified as a result of stress and deformation. Comparative analysis of both shafts was not found in the literature. As a result, the values of stress and deformation increased as the speed increases in both shafts. Stress and deformation increased as the pressure increases associated with the speed applied on the crankpin journal. The stress in the crankshaft of the single cylinder engine was critically occurring on main journal, and the stress in the crankshaft of the four-cylinder engine was critically occurring on the crankpin journal. This much of the stress in the single cylinder engine crankshaft reduces the working life of the shaft. The shaft material should be selected considering the working conditions in crankshaft, or the material should be improved by coating the main journal and crankpin journal.

The results of experimental studies of the operation of a D-242 diesel engine with hydrogen additives, as well as on the operation of an aluminum–hydrogen generator, are presented. The main parameters measured in the course of the experiments with the diesel engine and the aluminum–hydrogen generator under their joint operation in an automatic mode are presented. A structural diagram of an electronic control system for joint supply of fuel and hydrogen additives to a diesel engine of a vehicle is presented that makes it possible to maintain a preset crankshaft rotation speed and engine power in an automatic mode. The proposed solutions can improve the efficiency of vehicle diesel engines and, as a result, reduce the fuel consumption and level of hazardous emissions into the environment.

For critical steel engine parts, such as crankshafts, the fatigue strength under the critical working condition is usually improved by the electromagnetic induction quenching technique. In a previous study, the strengthening effect of this approach was always evaluated by a constant, which may result in some errors with the change of the technological parameters. In this paper, a type of steel crankshaft is selected to study the strengthening effect of this approach; first a local sub model composed of the crankpin is built to simulate the magnetic–thermal coupling process, then, the residual stress field is determined by simulating the whole course of fabrication. Finally, the prediction of the fatigue limit load is proposed based on the residual stress and the strength parameters of the material. The experimental verification shows that, when compared to the general means of modification models, the modified McDiarmid multi-axial fatigue model is more suitable to be applied to analyze the fatigue property of this quenched crankshaft due to the markedly higher accuracy. Based on this study, a new fatigue-limit load-prediction approach of this kind of crankshaft can be proposed for engineering applications.

U sklopu ovoga rada je na temelju usporedbe usporedbe uravnoteženosti zvjezdastog motora s glavnom klipnjačom i zvjezdastog motora bez glavne klipnjače opisan problem neuniformnosti gibanja klipova i dan je pregled postojećih rješenja za eliminaciju neuniformnosti. Na koncu je jedno od rješenja odabrano i provedena je analiza naprezanja tako dobivenog klipnog mehanizma. In this thesis the nonuniformity of the piston motion of a radial engine is shown by comparison of the kinematics and dynamics of conventional radial engines and masterless radial engines. A review of existing solutions is given. Finally, one solution to the nonuniformity problem is selected and stress analyses of the cranktrain are carried out.

In this study, a dynamic model of a single-cylinder four-stroke diesel engine has been created, and the crankshaft speed fluctuations have been simulated and validated. The dynamic model of the engine consists of the motion equations of the piston, conrod, and crankshaft. Conrod motion was modeled by two translational and one angular motion equations, by considering the kinetic energy resulted from the mass moment of inertia and conrod mass. Motion equations involve in-cylinder gas pressure forces, hydrodynamic and dry friction, mass inertia moments of moving parts, starter moment, and external load moment. The In-cylinder pressure profile used in the model was obtained experimentally to increase the accuracy of the model. Pressure profiles were expressed mathematically using the Fourier series. The motion equations were solved by using the Taylor series method. The solution of the mathematical model was performed by coding in the MATLAB interface. Cyclic speed fluctuations obtained from the model were compared with experimental results and found compitable. A validated model was used to analyze the effects of in-cylinder pressure, mass moment of inertia of crankshaft and connecting rod, friction, and piston mass. In experiments for 1500, 1800, 2400, and 2700 rpm engine speeds, crankshaft speed fluctuations were observed as 12.84%, 8.04%, 5.02%, and 4.44%, respectively. In simulations performed for the same speeds, crankshaft speed fluctuations were calculated as 10.45%, 7.56%, 4.49%, and 3.65%. Besides, it was observed that the speed fluctuations decreased as the average crankshaft speed value increased. In the simulation for 157.07, 188.49, 219.91, 251.32, and 282.74 rad/s crankshaft speeds, crankshaft speed fluctuations occurred at rates of 10.45%, 7.56%, 5.84%, 4.49%, and 3.65%, respectively. The effective engine power was achieved as 5.25 kW at an average crankshaft angular speed of 219.91 rad/s. The power of friction loss in the engine was determined as 0.68 kW.

Ushbu maqola texnika oliy ta���lim muassasalarida ���Avtomobillar konstruktsiyasi��� fanini o���qitishda dvigatelning tashqi tezlik xarakteristikasini qurish avtomobil sohasida ta���lim oluvchi talabalar uchun sodda va tushunarli usulda bajarilgan. Ushbu usuldan foydalanish orqali fan bo���yicha loyihalash konstruktorlik masalalarini bajarishda, fanni o���qitish jarayonida samarali natijalarga erishish mumkin., This article describes the construction of the external speed characteristics of the engine when teaching the subject "construction of cars" in technical universities in a simple and understandable form for students studying in the automotive industry. Using this method, you can achieve effective results in the learning process and solving design problems in the subject.

Overlapping regions of laser surface treatment are necessary features when processing large surface areas or cylindrical specimens. However, complex microstructural changes that appear in the regions with multiple heat treatment can affect their mechanical properties. Therefore, this study focuses on examining thermal cycle characteristics and resulting microstructures, particularly martensite and retained ferrite structures, to better understand the correlation between experienced thermal cycles and resulting microstructures. Laser surface hardening experiments on 44MnSiVS6 microalloyed steels together with thermal diffusion simulations were conducted to relate microstructures after the secondary pass of the laser treatment to the local thermal cycles experienced during the process. The amount of retained ferrite was calculated and compared to the respective thermal cycle characteristics. Regions which experienced thermal cycles below Ac3 temperature showed microstructures similar to those after tempering. The sizes of retained ferrite structures were found to decrease as the total holding time increases regardless of how the holding time is distributed in multiple laser treatments. However, the size of retained ferrite structures were constant in the region where tempering effect occurred. This shows that the amount of retained ferrite can be tailored by modifying the experienced total holding time and a reduction of retained ferrite structure happens only if the secondary thermal cycle is above Ac3 temperature. Validerad;2022;Nivå 2;2022-03-04 (hanlid);Funder: Research Fund for Coal and Steel, RFCS (754155 and 800726)

The present paper analyzes the damage of surfaces at spots of frictional contact, namely, the friction nodes on a camshaft and the connecting rod pins of a crankshaft. The resulting wear of the monitored friction nodes reduces the technical life of the machines, which can lead to the decommissioning of the machine. Wear was assessed by measuring roughness and microhardness and by observing the microstructures of the materials. The results of the experiments show that the rotating parts displayed visible wear on the cams, as well as on the connecting rod pins. The experiments revealed that wear was caused by the heating of the material to a high temperature during the operation of the machine and that there was a gradual cooling and tempering of the material, which led to a reduction in the microhardness of the monitored object. Lower microhardness values can be a cause of greater wear of the monitored objects. When comparing the microhardness of the used and the new camshaft, the hardened layer of the new camshaft from secondary production has a significantly smaller thickness compared to worn cams, which leads to the finding of a different material quality compared to the original parts from primary production. This fact indicates that the wear of a new camshaft as a spare part can contribute to the shortening of the technical life of friction nodes. Web of Science 15 1 art. no. 158

In order to explore the failure mechanism of a reciprocating compressor system with clearance fault, we implemented a computational framework whereby a simulation model of the mechanism is established using ADAMS software in this paper, and a typical reciprocating compressor model is introduced to validate the design model. In this work, the joint clearance faults between the crankshaft and linkage, between the linkage and crosshead, and in both locations are taken into account computationally. These faults are one of the major causes of vibration. Through dynamic calculation and analysis of a system with clearance fault, the simulated results show that these clearance faults directly influence the vibration. The larger the gap size, the more severe the vibration and the higher the amplitude of the vibration. Furthermore, the clearance number also affects the vibration greatly.

Diesel engine anti-shock performance is important for navy ships. The calculation method is a fast and economic way compared to underwater explosion trial in this field. Researchers of diesel engine anti-shock performance mainly use the spring damping model to simulate the main bearings of a diesel engine. The elastohydrodynamic lubrication method has been continuously used in the main bearings of diesel engines in normal working conditions. This research aims at using the elastohydrodynamic lubrication method in the main bearings of the diesel engine in external shock conditions. The main bearing elastohydrodynamic lubrication and diesel engine multi-body dynamics analysis is based on AVL EXCITE Power Unite software. The external shock is equivalent to the interference on the elastohydrodynamic lubrication calculation. Whether the elastohydrodynamic lubrication algorithm can complete the calculation under interference is the key to the study. By adopting a very small calculation step size, a high number of iterations, and increasing the stiffness of the thrust bearing, the elastohydrodynamic lubrication algorithm can be successfully completed under the external impact environment. The calculation results of the accelerations on engine block feet have a similar trend as the experiment results. Diesel engines with and without shock absorbers in external shock conditions are calculated. This calculation model can also be used for diesel engine dynamics calculations and main bearing lubrication calculations under normal working conditions.

During the crankshaft machining process, its axis of rotation does not coincide with the axis of rotation of the connecting rod neck. Therefore, the depth of a cut is always greater than the value of the allowable removed. It leads to uneven removal of allowance, reduces productivity and the quality of machining. The paper proposes a modular spatial model of removing the allowance and shaping of the root and connecting rod necks of the crankshafts during milling with crossed axes of the tool and part for one institution. Based on the developed model, the research of the formation of radical and connecting rod necks of a cranked shaft has been carried out. A method of milling the root and connecting rod necks of the crankshaft with crossed tool axes and parts has been presented, where the angle of rotation of the tool is selected from the condition of ensuring the straightness of the forming neck. In this case, the rough allowance is removed at the end, and the final allowance and calibration - the periphery of the cutter plate, which rotates and simultaneously performs the vertical and transverse movement, and the shaft performs a uniform rotation. The proposed method of milling provides stabilization of the depth of a cut along with the profile of the connecting rod necks, the area of the removed allowance, and the feed rate along the contour of the part.

This paper studies the high-pressure common-rail diesel engine fuel supply compensation based on crankshaft fragment signals in order to improve the uneven phenomenon of diesel engine fuel supply and realize high efficiency and low pollution combustion. The experiments were conducted on a diesel engine with the model of YN30CR. Based on the characteristics of crankshaft fragment signals, the proportional integral (PI) control algorithm was used to quantify the engine working nonuniformity and extract the missing degree of fuel injection. The quantization method of each cylinder working uniformity and algorithm of fuel compensation control (FOC) based on crankshaft fragment signal were established, and the control strategy of working uniformity at different operating conditions was put forward. According to the principle of FOC control, a FOC control software module for ECU was designed. The FOC software module was simulated on ASCET platform. The results show that: Compared with the traditional quantization method, the oil compensation information extracted from crankshaft fragment signal has stronger anti-interference and more accurate parameters. FOC algorithm can accurately reflect the engine's working nonuniformity, and the control of the nonuniformity is reasonable. The compensation fuel amount calculated by FOC is high consistency with the fuel supply state of each cylinder set by experiment, which meets the requirement of accurate fuel injection control of common-rail diesel engine.