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The aim of this study was to explore the vibration challenges caused by the crankshaft design in the air pump of the power integration device for steering and brake assistance in new energy buses. Three distinct crankshaft structures were designed and transient dynamic analysis was conducted using ANSYS software to assess the stress conditions and obtain the torque curves at the center points of these structures. Three newly fabricated crankshaft prototypes were subjected to vibration intensity tests on the integrated device. The experimental results revealed that the assistance device using the new crankshaft significantly reduced vibration intensity. [ABSTRACT FROM AUTHOR]

This research aims to study the mechanical behavior of the materials most commonly used in crankshaft manufacturing by designing a four-piston crankshaft, analyzing the stresses and displacements resulting from the applied load, and determining vibration frequencies. Additionally, this study examines the thermal behavior of the crankshaft. For this purpose, a three-dimensional model of the crankshaft was designed using CATIA V5 R18 software, and finite element analysis was subsequently performed using ANSYS 2019 R1 software under static, dynamic, and thermal conditions with four different materials in various orientations. To verify the effectiveness of the proposed design, it was compared with a reference design in terms of stresses and displacements. This study also explores improvements in crankshaft geometry and shape. The results indicate that selecting the appropriate material for the working conditions and optimizing the geometry and shape enhance engine performance and reduce the crankshaft's weight by 20%. The findings were validated by comparing the designs, which support increased productivity and improved durability. [ABSTRACT FROM AUTHOR]

The crankshaft is one of the most important parts of the engine and is likened to the "backbone" of the engine. In this paper, NL9340 high power diesel engine crankshaft system as the research object, the finite element free mode simulation model of crankshaft was established, and the inherent frequency and vibration mode of crankshaft were calculated. Through the rigid-flexible coupling finite element simulation of the crankshaft system, the dynamic and kinematic characteristics of the crankshaft system were analyzed. It was calculated that the load spectrum of each cylinder connecting rod journal and piston pin mainly fluctuated in the range of 20000 kN, in which the maximum exciting forces of the first connecting rod journal and the second connecting rod journal are above 30000 kN. On this basis, the static strength of the crankshaft was simulated and analyzed. The results show that the stress is the greatest and most concentrated at the over-rounded corner between connecting rod journal and crank. The maximum equivalent stress and deformation occur at the second cylinder connecting rod journal, which are 14.103 MPa and 8.3683 e-3 mm respectively. [ABSTRACT FROM AUTHOR]

Investigation was conducted on the failure of the crankshaft made from 48MnV alloy steel used in automotive engines. Magnetic flaw defects were detected at the transition fillet between the third main journal and the counterweight of the crankshaft. Macroscopic examination, chemical composition analysis, metallographic analysis, and scanning electron microscopy observation were performed on the crankshaft samples. The testing results were summarized, and the causes of the crankshaft cracking were systematically analyzed. The results indicate that longitudinal cracks occurred on the surface of the crankshaft journal due to the combined effect of thermal stress and normal operating stress, exceeding its load-bearing capacity. These cracks propagated inward, forming magnetic flaw cracks, ultimately leading to crankshaft failure.

This research aims to study the mechanical behavior of the materials most commonly used in crankshaft manufacturing by designing a four-piston crankshaft, analyzing the stresses and displacements resulting from the applied load, and determining vibration frequencies. Additionally, this study examines the thermal behavior of the crankshaft. For this purpose, a three-dimensional model of the crankshaft was designed using CATIA V5 R18 software, and finite element analysis was subsequently performed using ANSYS 2019 R1 software under static, dynamic, and thermal conditions with four different materials in various orientations. To verify the effectiveness of the proposed design, it was compared with a reference design in terms of stresses and displacements. This study also explores improvements in crankshaft geometry and shape. The results indicate that selecting the appropriate material for the working conditions and optimizing the geometry and shape enhance engine performance and reduce the crankshaft’s weight by 20%. The findings were validated by comparing the designs, which support increased productivity and improved durability.

As modern diesel engine design progresses toward higher burst pressure and power density, strict performance indices impose greater demands on the structural strength and reliability of crankshafts. We integrated finite element analysis and strength testing methods to achieve a lightweight crankshaft design. A comparison of the simulated results with the test data revealed that the crankshaft safety factor surpassed the permissible safety factor by 3.5 times, demonstrating significant safety redundancy in the design. We employed topology optimization techniques to create various crankshaft optimization models, yielding near-optimal solutions. Consequently, we identified the crankshaft with the best overall performance following comparative evaluations. We examined the influence of the fillet structure on the safety factor to mitigate stress concentration issues. Through multibody dynamic fatigue analysis, optimizing the crankshaft fillet resulted in a 6~7% increase in the safety factor. The minimum safety factor for the designed crankshaft was 1.6 times higher than the material permissible safety factor, which was 1.15. Utilizing the developed transient dynamics model of the lightweight crankshaft and a backpropagation genetic algorithm, we created a crankshaft fillet design tool to streamline the design process, which holds significant importance for the marine engine sector. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the failure and resonance of crankshaft under actual working conditions, taking the crankshaft of five-opposed plunger pump as an example, the theoretical analysis, simulation analysis, structural optimization and strength check of crankshaft under multiple working conditions were studied. Firstly, the ANSYS finite element analysis method was used to study the stress-strain nephogram and modal response nephogram of the crankshaft of 5DW150/16 opposed plunger pump under multiple working conditions, and the dangerous section and resonance problem of the crankshaft under different working conditions were analyzed. Then, the support structure optimization and response surface method optimization was used to study the influence of support mode and structural parameters on the stress and strain of crankshaft. Finally, the theoretical formula strength check was used to study whether the crankshaft before and after optimization meets the design requirements. The research results show that the dangerous section of the crankshaft of the five-throw two-support structure appears at the transition fillet of the crank pin, and there is no resonance phenomenon. The full support structure can enhance the impact resistance of the crankshaft, reduce the vibration of the crankshaft, improve the overall load capacity, and ensure the smooth operation of the pump. The maximum equivalent stress of the crankshaft optimized by the response surface method is reduced by 15. 8%, and the maximum deformation is reduced by 14. 04%. The crankshaft before and after optimization meets the strength requirements [ABSTRACT FROM AUTHOR]

This paper focuses on the optimization of a crankshaft using ANSYS software in terms of weight and strength. The initial designs of the crankshaft, piston, and connecting rod were created using SolidWorks. The force generated by the gas during the combustion process was calculated to be 12017 N. Next, the SolidWorks assembled system was imported into ADAMS View software for simulation, which revealed a time-variant force of the crankpin of 14049 N. The calculated value was verified with results obtained from analytical calculations, showing a deviation of 0.23%. Finite element analysis was done for the crankshaft using ANSYS transient structural after applying loadings and boundary conditions. The optimization process aimed to minimize the crankshaft's weight while maintaining its strength and durability. The results of the ANSYS simulations showed a weight reduction of 2.5% from the original 2.983 kg to 2.907 kg, while maintaining the required strength and durability. The optimized crankshaft was compared to its original design in terms of fatigue life, weights, and stresses. The maximum von Mises stress was reduced by 16%, shear stress by 3.5%, and deformation by 3.5%, which were validated through analytical calculations. The crankshaft analysis resulted in a significant increase in fatigue life, calculated to be infinite under the given conditions. To conclude, the objective to optimize the crankshaft for performance and efficiency was achieved, demonstrating a 2.5% weight reduction and substantial improvements in fatigue life and stress distribution, proving the effectiveness of ANSYS software for the design optimization process. [ABSTRACT FROM AUTHOR]

We developed the outboard motor (OM) equipped with a new V8 type engine with a V-bank angle of 60 degrees. In OMs, the low vibration performance is important to provide the comfortable cruising. However, in this type of engine, the conventional crankshaft cannot cancel the inertial couples. Additionally, because high rpm range mainly used in OMs, the inertial couples contribute to the engine vibrations. In this paper, we proposed the new crankshaft which can cancel them with no additional parts such as balancers. In the examination of the structure, we performed the parametric study of the crankpin offset angle and the counterweight balance ratio. Finally, adopting the new crankshaft to the OM, we achieved the low vibration performance. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effect of grain size of an initial microstructure (pearlite + ferrite) on a resulting microstructure of induction-hardened microalloyed steel 38MnVS6, which is one topical medium carbon vanadium microalloyed non-quenched and tempered steel used in manufacturing crankshafts for high-power engines. The results show that a coarse initial microstructure could contribute to the incomplete transformation of pearlite + ferrite into austenite in reaustenitization transformation by rapid heating, and the undissolved ferrite remains and locates between the neighboring prior austenite grains after the induction-hardening process. As the coarseness level of the initial microstructure increases from 102 μm to 156 μm, the morphology of undissolved ferrite varies as granule, film, semi-network, and network, in sequence. The undissolved ferrite structures have a thickness of 250–500 nm and appear dark under an optical metallographic view field. To achieve better engineering applications, it is not recommended to eliminate the undissolved ferrite by increasing much heating time for samples with coarser initial microstructures. It is better to achieve a fine original microstructure before the induction-hardening process. For example, microalloying addition of vanadium and titanium plays a role of metallurgical grain refinement via intragranular ferrite nucleation on more sites, and the heating temperature and time of the forging process should be strictly controlled to ensure the existence of fine prior austenite grains before subsequent isothermal phase transformation to pearlite + ferrite. [ABSTRACT FROM AUTHOR]

Existing optimization research on the crankshaft heat treatment process is mostly based on one-sided considerations, and less consideration is given to the matching of multiple process parameters, leading to irrational designs of heat treatment. To address this problem, this work investigates the influence mechanisms of cooling speed, tempering temperature, and holding time on the performance evaluation indexes of the straightness, residual stress, and martensite content of a crankshaft based on the response surface method. The results showed that the order of influence of these three different process parameters on the performance evaluation index was cooling speed > holding time > tempering temperature, and the order of influence on the performance evaluation indexes under multifactorial process parameters was cooling speed–holding time > cooling speed–tempering temperature > holding time–tempering temperature. The optimal process parameters were a cooling speed of 1.4 times the cooling oil, a tempering temperature of 555 °C, and a holding time of 6 h, with the straightness of the crankshaft reduced by 9.9%, the surface stress increased by 6.7%, and the martensitic content increased by 7.2% after the process optimization. This work can provide new clues for optimizing the heat treatment process parameters of crankshafts. [ABSTRACT FROM AUTHOR]

Currently, variable compression ratio engines are not used, presumably due to the complexity of the design. Currently, various engines are being developed that differ in design, kinematics, load control and compression ratio changes. The article presents the results of calculating the efficiency and fuel consumption for a crankshaft with a rotation speed of 2000 and 4000 rpm with a compression ratio of 8.6 and a rotation speed of 4000 rpm with a compression ratio of 13 and provides combustion characteristics m = 3 and 1. It is shown that these characteristics at higher speeds they approach the indicators at lower speeds with an increase in the compression ratio. The engine parameters were calculated for various modes based on Wiebe theory. Based on the calculations, the efficiency and fuel consumption are determined for the corresponding modes and the nature of the engine operation. It has been found that with an increase in the crankshaft rotation speed, the cycle efficiency will decrease by almost half and fuel consumption will increase accordingly; with an increase in the compression ratio, the efficiency is restored and fuel consumption decreases accordingly. [ABSTRACT FROM AUTHOR]

Investigation was conducted on the failure of the crankshaft made from 48MnV alloy steel used in automotive engines. Magnetic flaw defects were detected at the transition fillet between the third main journal and the counterweight of the crankshaft. Macroscopic examination, chemical composition analysis, metallographic analysis, and scanning electron microscopy observation were performed on the crankshaft samples. The testing results were summarized, and the causes of the crankshaft cracking were systematically analyzed. The results indicate that longitudinal cracks occurred on the surface of the crankshaft journal due to the combined effect of thermal stress and normal operating stress, exceeding its load-bearing capacity. These cracks propagated inward, forming magnetic flaw cracks, ultimately leading to crankshaft failure. [ABSTRACT FROM AUTHOR]

In the grinding process of crankshafts, the grinding parameters were improperly selected, which easily caused the high temperature in the grinding zone and led to burns on the crankshaft journal surface. To address this issue, referencing previous studies, the suitability of the Gaussian heat source model was verified by comparing it with three different heat source models. The Gaussian heat source model was applied to predict the temperature on the surface of the crankshaft connecting rod journal. Transient thermal analysis and investigation of material phase transformation were employed to explore the mechanism of grinding burns. The interaction effects among grinding parameters were analyzed using the Box-Behnken design, and a multiple linear regression equation was established for response surface optimization. The results demonstrated that applying the Gaussian heat source model and response surface optimization yielded the optimal solution, with a maximum deviation of 1.37% between the simulation and optimization results. By selecting a grinding depth (ap) of 0.40 mm, wheel speed (vs) of 40.00 m/s, and feed rate (vx) of 0.036 mm/s as the processing parameters, the temperature in the grinding zone was reduced to 659.37 °C, effectively mitigating grinding burns. [ABSTRACT FROM AUTHOR]

A method for preliminary assessment of the ratio of the flow sections areas of the suction and discharge valves in a piston hybrid energy machine with regenerative heat exchange when operating in pump and compressor modes at a constant angular velocity of the crankshaft is developed. It is shown that this ratio in pump mode should be twice as large as in compressor mode. The basic designs of self-acting valves in piston compressors and piston pumps are considered. Options for improving the designs of suction and discharge valves of piston hybrid energy volumetric machines with regenerative heat exchange are proposed. [ABSTRACT FROM AUTHOR]

The development of lightweight components in the automotive industry is an important aspect in designing of products aiming to reducing fuel consumption, optimal use of material resources and sustainability. The optimization of internal combustion engines (ICE) components can be performed for example by mass subtraction procedure and use of different materials. Optimizing crankshafts is challenging due to the applied bending and torsion loads that increase the stress concentrations in critical regions. In this context, the objective of the present work is to propose a numerical approach for fatigue assessment of crankshafts, which must reduce the number of specimens required in experimental tests and the development costs. The stress distribution of a commercial crankshaft model was determined numerically from harmonic response analysis, and correction factors related to surface treatments and failure criterion were applied for estimating the fatigue strength. The fatigue strength estimated numerically was compared to experimental fatigue tests results, and this methodology was also applied to a lightweight model obtained by means of mass reduction. The fatigue strength estimation showed 2 % and 7 % relative error for the original and lightweight crankshaft models, respectively. In addition, both numerical and experimental results achieved about 10 % of mass reduction for the commercial crankshaft without considerable influence on the bending and torsion fatigue strength. The present work indicates that the proposed numerical approach can predict with good accuracy the fatigue strength of crankshafts during the design stage.

This study outlines the development of a three-dimensional model for the crankshaft-bearing and a multi-body dynamics model for a four-stroke marine diesel engine. The models are constructed through a simulation approach that integrates the finite element method and multi-body dynamics method. Additionally, the Greenwood/Tripp asperity contact theory and average flow model are incorporated. The investigation also delves into the dynamic coupling between the crankshaft-bearing multi-body system and the mixed lubrication effects, accounting for lubricating oil as a thermo-electrohydrodynamic model and the journal as an elastomer. The study meticulously examines the lubrication characteristics of main bearings in marine diesel engines during normal operational conditions and scrutinizes the impact of various parameters on crankshaft-bearings. The study concludes by offering recommendations and technical support for innovative optimization design and model enhancement of diesel engine crankshaft-bearings.

This paper originally investigates the sulfide inclusion-induced micro-scaled pitting corrosion in indoor atmospheric environment on automotive crankshafts manufactured by classical non-quenched and tempered steel using scanning electron microscope using energy-dispersive spectrometer. The crankshafts, which were disassembled from gasoline engines with low mileage after specific tests, were stored in an indoor atmospheric environment with an ambient humidity of approximately 75% for 2 weeks. The experimental results show that the anodic reaction initially took place at the sulfide inclusion/steel matrix interface, which was induced by the sulfide inclusion wherever very small amount of residual neutral chloride medium on the crankshaft surface was activated by moisture in the air. In addition, the reaction products could accelerate the rate of pitting corrosion toward the steel matrix in nearby micro-zones, and tiny rust that could be hardly observed by visual inspection, as a result, appeared in micro-scale on the experimental crankshaft surface even in indoor atmospheric environment. It is concluded that even when the crankshaft is stored indoors, special attention should be pertinently paid to corrosion prevention, for example, to remove all corrosive media on surface carefully by fine cleaning, to implement rust prevention measures, and to control humidity of atmospheric environment at a proper level. [ABSTRACT FROM AUTHOR]

A theoretical virtual machining method is proposed to identify the optimal machining center-line. The process initiates with a meticulous scanning and reverse reconstruction of forged crankshafts model, which is then discretized into numerous pieces for assessing imbalance force and moment. An iterative process is introduced to search for the mass center-line of the crankshaft, followed by a virtual machining method to obtain the virtual final product. An optimization procedure is employed to accurately identify the distances between the optimal machining center-line and the mass center-line. It can be theoretically applied in CNC crankshaft mass centering machines to determine offset values. [ABSTRACT FROM AUTHOR]

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dynamometers are equipment that has been widely used in the field of electric machines test benches. A dynamometer system has the ability to create intricate and unpredictable behaviors of mechanical loads according to a programmed manner. Extensive research into the characteristics of loads found in industrial settings has shown that non-linear and complex phenomena, including misalignment, mechanical friction, and others, are unavoidable in industrial drive systems. To assess the performance of motor and drive systems in industrial drives when subjected to these non-linear and complex loads, a fast and precise dynamic drive system must track high-frequency torque signals with precision. The suggested dynamometer, serving as an instrumental device, has the ability to emulate a wide torque response across various frequencies during both transient and steady-state conditions for the machine under test. Simulations and experimental results confirm the dynamometer's wide-ranging dynamic response, enabling the emulation of different linear and non-linear loads. [ABSTRACT FROM AUTHOR]

The ultrasonic impacting process was carried out on the fillet of 34CrNi3MoA steel crankshaft treated by quenching and tempering, medium frequency quenching and gas nitriding respectively, and the variations of surface integrity of crankshaft were analyzed. The results show that the Ra of fillet can be decreased to below 0.2 µm after the ultrasonic impacting. The ultrasonic impacted crankshaft with initial process of gas nitriding has the highest hardness but the lowest hardness increase rate due to its high deformation resistance of nitriding layer. The ultrasonic impacting can transfer the tensile residual stress to the compressive residual stress on the fillet, the specimens with initial process of gas nitriding exhibit the highest compressive residual stress of −412.17 MPa. The fatigue performance model of the crankshaft was established based on Basquin and Goodman equations, the crankshaft treated by gas nitriding and ultrasonic impacting is supposed to have the highest fatigue limit. [ABSTRACT FROM AUTHOR]

A method for calculating the counterweight mass of a crank-and-rod mechanism for designing a piston drive or pump is proposed. The method provides a rational combination of mass, overall dimensions, and values of wear and power loss in the bearing with maximum balance. Calculations are carried out using the MathCAD software. The optimal ranges of the parameters are given. The criterion for the best balance of the crank-and-rod mechanism is introduced to calculate the counterweight mass. Determinations of displacements, velocities, accelerations, and reaction forces are based on d'Alembert's principle in vector form for each moment in time. [ABSTRACT FROM AUTHOR]

The relevance of the topic of the article is due to the unresolved problem of failures of automobile engines, in particular, modern mass-produced engines of the KAMAZ-740.10, 7403 families, due to cranking of the connecting rod bearings, and the need for deeper studies of the processes and phenomena that lead to them, and the development of solutions that exclude them in operation. The purpose of the study is to ensure the reliability of automobile engines by reducing the risk of crankshaft connecting rod bearings turning in operation by developing a method for studying their shape change and applying it when substantiating and implementing various design, technological and operational solutions. A prototype is described and a developed method and device for determining the clearance in a connecting rod bearing, suitable for studying the formation of connecting rod bearings under engine test bench conditions. The prototype was a differential-type pneumatic device used in active control devices for honing cylinder liners. With the use of the described device, a method for studying the formation of connecting rod bearings under the conditions of bench tests of KAMAZ-740.10 diesel engines was developed and tested. The use of new methods, devices and techniques makes it possible to investigate the patterns of shape changes of connecting rod bearings in relation to lubrication conditions, temperature and load conditions of the engine, and other factors. The presented experimental results show that the gap in the connecting rod bearing is not stable, is caused not only by wear, but also by the resulting deflection of the liner, and significantly depends on the temperature regime of the engine - with an increase in oil temperature, the gap decreases due to an increase in deflection. The authors explain the formation of deflection and shape change of the liners by the loss of its stability from the action of loads and internal stresses under conditions of instability of the oil supply. The results of experimental studies presented in the article have a scientific novelty, since a previously undescribed and not fixed decrease in the gap due to the deflection of the liners, which is formed immediately from the start of operation after the engine is assembled, is established, and its value is variable and determined by the temperature regime. Practical significance – the developed method makes it possible to study the formation patterns of crankshaft connecting rod bearings to test the effectiveness of design, technological and operational solutions to prevent their turning during the operation of an automobile engine. The main directions of promising research is the substantiation of practical solutions to ensure the stability of the shape of the liners during long-term operation of the engine.

Fatigue performance of RV-20E reducers is investigated experimentally herein; load and life curves of RV-20E with different crankshaft heat treatment strengthening processes are obtained. The optimum surface microstructure and optimum surface hardness of the crankshaft for improving the fatigue life of the RV-20E reducer are analyzed, and the failure mode and failure mechanism of the crankshaft of the RV-20E reducer are discussed. Based on the S-N theory and the Miner theory, and combined with the force analysis of RV-20E, the life parameter of RV-20E reducers based on the crankshaft needle roller bearing assembly is derived, and the test data is compared and analyzed. The analysis and comparison show that the life parameter can effectively correlate the fatigue life of RV-20E reducers and can be used to predict the fatigue life of RV-20E reducers.

As modern diesel engine design progresses toward higher burst pressure and power density, strict performance indices impose greater demands on the structural strength and reliability of crankshafts. We integrated finite element analysis and strength testing methods to achieve a lightweight crankshaft design. A comparison of the simulated results with the test data revealed that the crankshaft safety factor surpassed the permissible safety factor by 3.5 times, demonstrating significant safety redundancy in the design. We employed topology optimization techniques to create various crankshaft optimization models, yielding near-optimal solutions. Consequently, we identified the crankshaft with the best overall performance following comparative evaluations. We examined the influence of the fillet structure on the safety factor to mitigate stress concentration issues. Through multibody dynamic fatigue analysis, optimizing the crankshaft fillet resulted in a 6~7% increase in the safety factor. The minimum safety factor for the designed crankshaft was 1.6 times higher than the material permissible safety factor, which was 1.15. Utilizing the developed transient dynamics model of the lightweight crankshaft and a backpropagation genetic algorithm, we created a crankshaft fillet design tool to streamline the design process, which holds significant importance for the marine engine sector.

In this study, we investigated the effect of grain size of an initial microstructure (pearlite + ferrite) on a resulting microstructure of induction-hardened microalloyed steel 38MnVS6, which is one topical medium carbon vanadium microalloyed non-quenched and tempered steel used in manufacturing crankshafts for high-power engines. The results show that a coarse initial microstructure could contribute to the incomplete transformation of pearlite + ferrite into austenite in reaustenitization transformation by rapid heating, and the undissolved ferrite remains and locates between the neighboring prior austenite grains after the induction-hardening process. As the coarseness level of the initial microstructure increases from 102 μm to 156 μm, the morphology of undissolved ferrite varies as granule, film, semi-network, and network, in sequence. The undissolved ferrite structures have a thickness of 250–500 nm and appear dark under an optical metallographic view field. To achieve better engineering applications, it is not recommended to eliminate the undissolved ferrite by increasing much heating time for samples with coarser initial microstructures. It is better to achieve a fine original microstructure before the induction-hardening process. For example, microalloying addition of vanadium and titanium plays a role of metallurgical grain refinement via intragranular ferrite nucleation on more sites, and the heating temperature and time of the forging process should be strictly controlled to ensure the existence of fine prior austenite grains before subsequent isothermal phase transformation to pearlite + ferrite.

The optimization of industrial products and processes has been, since the beginning of the third industrial revolution, a fundamental aspect of the design phase as it allows, together with the testing and validation phases, the improvement of the performance or efficiency of what has been designed. Optimization is also applied to the counterweights of the crankshafts that ensure the balancing of the forces and moments generated by internal combustion engines during their regular use. Traditionally, this process is carried out, at the preliminary stage, in an analytical way, using specific formulas for each engine configuration. This approach, however, allows the identification of only the macro-parameters of the counterweight, i.e. mass and position of the center of gravity, leaving the designer the translation into technical drawing of the result of the optimization. Thanks to the increase in computational power obtained in recent decades and the interconnection of systems, typical of Industry 4.0, this work intends to propose a new methodology for optimizing counterweights, based on a two step approach, able to identify the best solution not only in terms of macro-parameters, but also of the specific dimensional parameters of the counterweight.

The existence of friendly programming environments, which allow the transposition of models developed for different mechanical systems into numerical procedures, easy to access, make it necessary to develop models of mechanical systems used in industry. In this work, we propose to do this for an internal combustion engine. The offered model allows the unitary solution of problems of this type, which involves the calculation of the forces appearing in the engine elements. It offers the possibility to analyze different constructive types of engines. The model is a complex model that finally provides the forces existing in different elements of the engine as well as the developed engine torque. [ABSTRACT FROM AUTHOR]

The high-cycle bending fatigue experiment is one of the most important necessary steps in guiding the crankshaft manufacturing process, especially for high-power engines. In this paper, an accelerated method was proposed to shorten the time period of this experiment. First, the loading period was quickened through the prediction of the residual fatigue life based on the unscented Kalman filtering algorithm approach and the crack growth speed. Then, the accuracy of the predictions was improved obviously based on the modified training section based on the theory of fracture mechanics. Finally, the fatigue limit load analysis result was proposed based on the predicted fatigue life and the modified SAFL (statistical analysis for the fatigue limit) method. The main conclusion proposed from this paper is that compared with the conventional training sections, the modified training sections based on the theory of fracture mechanics can obviously improve the accuracy of the remaining fatigue life prediction results, which makes this approach more suitable for the application. In addition, compared with the system's inherent natural frequency, the fatigue crack can save the experiment time more effectively and thus is superior to the former factor as the failure criterion parameter. [ABSTRACT FROM AUTHOR]

The Crankshaft Full-automatic Measuring Machine (CFMM) features high accuracy, high efficiency and complete measurement parameters, and represents the forefront of a geometric crankshaft accuracy measuring instrument. One of its core technologies is the high-precision radial following the crankshaft connecting rod journal measurement. In this paper, an independent probe design scheme combining the flexible dual-complex parallel four-bar guide mechanism and double displacement sensors based on the contact measurement method was proposed. It was suitable for the measurement of precision parts with eccentric characteristics such as crankshaft and camshaft measurement. Taking the spring as the flexible part, the probe prototype’s optimization design, processing and assembly were completed, the test device was built, and the system accuracy was calibrated under various positions and feed quantities of the probe. The results revealed that the expanded measurement uncertainty after double-sensor compensation was enhanced from 1.53 μm in single-sensor measurement to 0.44 μm, satisfying the high-precision requirements of engineering measurement accuracy and reducing the measurement cost.

When developing the technological process of cast iron crankshaft restoring, it is necessary to obtain a martensitic structure in the pad weld in order to ensure the wear resistance needed. To form the martensitic structure the cooling rate after padding must be at least 80 - 90 0°C / s. The helical surface welding does not lead to such a result, so in our research we use the welding according to the width of the shaft neck. We also examined the heat release from the pad weld and its cooling rate. For its implementation, the necessary calculations were made according to a compiled program in the QBASIC language. On the basis of these provisions, the theoretic background is proposed for the possibility of the wide-ringed welding of crankshaft necks, which ensures a minimal change in the structure and geometry of the crankshafts.

Problem. The most high-precision parts of the car engine are camshaft and crankshaft, parts that require two-sided processing of the end surfaces: piston pins, valve springs. Traditional processing methods are used in their manufacture and repair. Therefore, taking into account the large volumes of car production, the improvement of existing and development of new processing methods is very important. Goal. The purpose of this work is the analysis and improvement of existing methods and the implementation for new ones of processing the specified parts to increase the productivity and accuracy of their processing. Methodology. The processing of support necks and cams is expedient to be carried out in one installation during deep high-speed grinding with crossed axes of the circle and camshaft due to stabilization of the cutting depth and feed along the contour with uneven rotation of the part. The method of high-speed milling of camshaft cams with crossed axes of the tool and parts on CNC machines is also promising. Root and connecting rod necks of crankshafts can be processed in one installation by deep high-speed grinding with crossed axes of the circle and the part due to stabilization of the depth of cutting and feed along the contour with uniform rotation of the part. For end surfaces, it is possible to introduce single-pass processing on double-sided end grinding machines with oriented grinding wheels with calibration areas. Results. The obtained results indicate a 25-30% increase in productivity and processing accuracy of the specified parts. Originality. It is used when processing the effect of the intersection of the axes of the tool and the part and carrying out a special correction of the tool, which allows to obtain a calibration area. Practical value. The proposed methods improve the parameters of accuracy, roughness and productivity of processing, which is an important scientific and practical task, whose solution will allow to increase the service life of car components and assemblies, reduce the cost of their production, and raise the level of competitiveness of products and services.

A novel metaheuristic algorithm has been presented based on the physical significance of palm tree leaves and petioles, which can themselves water and fertilize with their unique architecture. Palm tree leaves collect almost all the raindrops that fall on the tree, which drags the nutrient-rich dropping of crawlers and birds that inhabit it and funnel them back to the palm tree's roots. The proposed Palm Tree Optimization (PTO) algorithm is based on two main stages of rainwater before it reaches the trunk. Stage one is that the rainwater drops search for petioles in the local search space of a particular leaf, and stage two involves that the rainwater drops after reaching the petioles search for trunk to funnel back to the root along with nutrients. The performance of PTO in searching for global optima is tested on 33 Standard Benchmark Functions (SBF), 29 constrained optimization problems from IEEE-CEC2017 and real-world optimization problems from IEEE-CEC2011 competition especially for testing the evolutionary algorithms. Mathematical benchmark functions are classified into six groups as unimodal, multimodal, plate & valley-shaped, steep ridges, hybrid functions and composition functions which are used to check the exploration and exploitation capabilities of the algorithm. The experimental results prove the effectiveness of the proposed algorithm with better search ability over different classes of benchmark functions and real-world applications. [ABSTRACT FROM AUTHOR]

The crankshaft, as the main detail in internal combustion engines, is subjected to a variable load caused by the dynamic forces of the combustion process and its rotation. As a result, its surface layers are loaded successively in tension and compression, which causes fatigue of the material. The destruction of crankshafts is a serious problem in the operation of internal combustion engines and creates serious costs for the maintenance of the vehicle fleet. In this research paper are presents the results of a study of damaged crankshafts from internal combustion engines. The failure mechanisms of steel and cast iron crankshafts were established, and penetrant testing was conducted to identify other fatigue cracks. The hardness of the material from which the crankshafts are made was measured, and no significant changes were found. The study was conducted on broken crankshafts from gasoline and diesel engines, and the fracture surface, hardness and local deformations of the main journals and crank pin journals were examined. The crankshafts are made of steel and cast iron, having been dismantled from a car with a mileage of about 300,000 km, a truck with a mileage of about 250,000 km and a forklift with about 8,000 motor hours. [ABSTRACT FROM AUTHOR]

The article presents simulation strength calculations of a newly designed crankshaft for a PZL 100 engine with a reciprocating piston design. This engine is the subject of a research and development project co-financed by NCBR. The article presents four successive versions of the crankshaft geometric changes which underwent strength calculations. Such elements as the outer and inner parts of the crankshaft arm were changed in these geometric versions. The geometry of the shaft was changed using Catia v5 software, while strength calculations were carried out in Abaqus software. In summary, one of the presented models was selected for further work due to the possible simplification of the manufacturing process and the reduction of mass and stresses. This model was further investigated in the project. [ABSTRACT FROM AUTHOR]