Browse Topic: Crankshafts
The increasing popularity of e-bikes, especially pedelecs, has led to a growing interest in consideration of e-bike cycling. To achieve a deeper understanding on the process of e-bike cycling and in particular the effects on the rider it can be instrumental to use simulation methods. In this context, the e-bike drive system and its function are of central importance for e-bikes. Therefore, this work proposes a functional modeling of the powertrain of an e-bike with a mid-drive motor, considering legal constraints and support functionalities. The model incorporates the mechanical transmission between pedals, motor, and crank shaft, allowing for a detailed analysis of the e-bike’s performance. Additionally, the support mechanism is depicted, where an electric motor amplifies the rider’s pedaling torque. The electrical behavior of the motor, energy consumption, and battery state of charge are also integrated into the model. This comprehensive approach aims to provide a generic
The power assist system of an electric bicycle uses a magnetostrictive torque sensor to detect the pedal force based on the magnetic properties of the crankshaft, which change according to stress. Fe–Ni alloy plating is used to coat the surface of the crankshaft with a magnetic film to enhance the magnetostrictive effect. However, the sensor performance decreases as the plating solution degrades, which necessitates replacement of the plating solution. In this study, experiments were performed to investigate how to prevent or mitigate degradation of the plating solution to reduce waste. The amounts of carbon and sulfur in the magnetic film were found to increase with degradation of the plating solution. The carbon derived from organic reducing agents and their decomposition products, and the sulfur derived from stress relievers and their decomposition products. A method was developed for reducing the amounts of carbon and sulfur in the magnetic film, which would help maintain the sensor
This paper explains transient, computationally rigorous, three-dimensional and one-dimensional multiphase CFD analysis of engine oil drainback system and lubrication system for predicting aeration. Aeration of engine oil is an important factor as it affects working of Hydraulic Lash Adjusters, bearings performance and it reduces lube system pressure itself which is detrimental for the entire engine. In this work specifically effect of engine tilting on lube oil aeration is presented. When engine is tilted, crankshaft and connecting rod/s are dipped in to oil, which creates air bubbles. These air bubbles travel to lube pump and then to the engine lube system. Therefore, it is essential to model aeration in Engine crankcase, Oil pan and Lube system for the purpose of predicting oil pressure reduction in lube system. The problem under consideration is spread over a bigger zone, involves rotating and translating components, passage’s dimensions are varying from microns to meters and
This research employs advanced Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations to analyze the transient multiphase flow dynamics within a four-cylinder inline (I-4) engine, with a focus on gas-liquid interface interactions and oil distribution phenomena. Utilizing a commercial three-dimensional Computational Fluid Dynamics (CFD) software suite, the study incorporates detailed crankshaft rotational kinematics and piston reciprocation to accurately model oil drawdown and retention across various operational conditions. A Volume of Fluid (VOF) approach is applied to assess the impact of crankshaft rotational speeds of 5000 rpm and 6500 rpm on oil distribution and aeration in the oil pan. Comprehensive computational analyses characterize oil-air distribution patterns, quantify oil flow rates through drainback pipes, and elucidate bubble formation dynamics within the sump. The study also examines the relative contributions of crankshaft rotation, piston pumping, and balance
Cooling system for an IC engine, consisting of the Water pump (WP), Radiator and Fan, plays an important role in maintaining thermal efficiency of the engine and protects the engine from overheating. Based on the vehicle application requirement, Fan will be mounted directly either on Crankshaft or WP pulley. But wherever increase in Fan speed ratio are in demand, it is preferred to mount the Fan on WP pulley. So it important to understand the WP housing structural strength with respect to vibration loads contributed from Radiator Fan assembly. This paper presents investigation of Failure of WP Housing during engine validation at engine test bed with Electronic Viscous Fan, based on the different operating conditions of the engine and fan as per the validation cycle. While the accessories are loading and the corresponding stresses are high when the fan is engaged. But in the current case, the failure of WP housing happened only during Fan clutch disengaged condition. Experimental
The development of new fuels for internal combustion engines (ICE) requires further technical support by understanding the pollutant formation mechanism in various phases of combustion so that emissions can be minimised. This research will therefore utilize a bespoke in-cylinder sampling system to analyse the precursors of Polycyclic Aromatic Hydrocarbons (PAHs) and Particulate Matter (PM) during bio-derived lactone combustion in a single-cylinder diesel engine. The sampling system was composed of a poppet-type in-cylinder sampling valve that displaced one of the engine’s intake valves and protruded into the combustion chamber beyond the flame quenching layer, and a Gas Chromatography Flame Ionization Detector (GC-FID) that analysed the samples. The sampling valve was electromagnetically actuated, and its operation was referenced to the engine crank shaft encoder allowing the valve to open at any crank angle degree (CAD) within a timing resolution of 0.2 CAD. Lactones are oxygenated
Engine off control is conducted on parallel hybrid vehicles in order to reduce fuel consumption. It is efficient in terms of fuel economy, however, noise and vibration is generated on engine cranking and transferred through engine mount on every mode transition from EV to HEV. Engine crank position control has been studied in this paper in order to reduce vibration generated when next cranking starts. System modeling of an architecture composed of an engine, P1 and P2 motors has been conducted. According to the prior studies, there exists correlation between crank vibration level and the crank angle. Thus a method to locate pistons on a specific crank angle which results in a local minimum of vibration magnitude could be considered. The P1 motor facilitates this crank position control when engine turns off, for its location directly mounted on a crankshaft allows the system model to obtain more precise crank position estimation and improved linearity in torque control as well. For the
In crank- train system, the prime objective of crankshaft is to facilitate the transformation of reciprocating motion of connecting rod into rotational motion at flywheel end. Moreover, the contribution of mass from crankshaft is in the same order as of flywheel assembly mass which accounts to approximately 40% to 50% of total mass of engine. Therefore, to accomplish the development of an efficient engine it is vital to optimize the crankshaft based on simulation parameters like balance rate, mass, torsional frequency, web shear stress etc. In the given work, crankshaft has been designed and developed for an engine used in light duty commercial vehicle. The defined work demonstrates the application of 1D simulation tool AVL Excite in development phase of the engine. To establish equilibrium between the weight and simulation guidelines, many iterations of models were evaluated and finally we were able to achieve mass reduction of nearly 8% from the base model. Thenceforth, validation of
The absence of combustion information continues to be one of the key obstacles to the intelligent development of engines. Currently, the cost of integrating cylinder pressure sensors remains too high, prompting attention to methods for extracting combustion information from existing sensing data. Mean-value combustion models for engines are unable to capture changes of combustion parameters. Furthermore, the methods of reconstructing combustion information using sensor signals mainly depend on the working state of the sensors, and the reliability of reconstructed values is directly influenced by sensor malfunctions. Due to the concentration of operating conditions of hybrid vehicles, the reliability of priori calibration map has increased. Therefore, a combustion information reconstruction method based on priori calibration information and the fused feature deviations of existing sensing signals is proposed and named the "Deviation-based Centroid Displacement Method" (DCDM). The method
To realize the dynamics concept “enjoy driving” of new-model cars, engine sound was based on the concept of “exhilarating.” To achieve “exhilarating,” we compared current models with competitor cars to understand the countermeasure sound characteristics. As a result, it was found that the rumble noise at low-RPM medium load needs to be reduced. To reduce rumble noise, the crankshaft system and power train stiffness were refined. As a result, we were able to achieve our goal of exhilarating engine sound. However, as the evaluation of sound after a vehicle is sold is generally left to the user, there are few studies that examine whether a car is more highly evaluated based on the sounds it creates. Therefore, this study was conducted to evaluate concept compatibility and loyalty in relation to exhilarating engine sound in the U.S. market for Generation Z, the target group for the new car. The reason we surveyed loyalty was because it was a fair evaluation indicator when examining the
In automotive Front End Accessory Drives (FEAD), the crankshaft supplies power to accessories like alternators, pumps, etc. FEAD undergoes forced vibration due to crankshaft excitation, dynamic tension fluctuations can cause the belt to slip on the accessory pulleys. By considering the criticality of the system, when engine mounting is longitudinally to the vehicle which makes it directly exposed to the air flow containing foreign particles which may cause the damage to the FEAD system and deteriorate the intended functionality. FEAD cover is introduced in the system to enhance belt-pully system functionality by restricting the entry of foreign particles during engine operation. This paper contains a study of FEAD cover failure and provides the stepwise approach to capture such issue during novel model development for 4 cylinder naturally aspirated engine during engine bench testing. The failure mechanism was studied using various methodology such as CAE and G-Load measurement to
Virtual sensing, i.e., the method of estimating quantities of interest indirectly via measurements of other quantities, has received a lot of attention in various fields: Virtual sensors have successfully been deployed in intelligent building systems, the process industry, water quality control, and combustion process monitoring. In most of these scenarios, measuring the quantities of interest is either impossible or difficult, or requires extensive modifications of the equipment under consideration – which in turn is associated with additional costs. At the same time, comprehensive data about equipment operation is collected by ever increasing deployment of inexpensive sensors that measure easily accessible quantities. Using this data to infer values of quantities which themselves are impossible to measure – i.e., virtual sensing – enables monitoring and control applications that would not be possible otherwise. In this concept paper, we provide a short overview of virtual sensing and
Internal combustion engines will play an important role in the coming decades, even considering targets of carbon neutrality for a sustainable future. This will be especially true in regions where pure electrified vehicle implementation is not yet practical, or for long-range heavy load transportation purposes, even in regions where BEV infrastructure is well established. HEV/PHEV’s importance and contribution to CO2 emission reduction together with carbon neutral fuels such as hydrogen, e-fuel and biomass fuel etc. will remain crucial regardless of region/transport sectors. In this respect, brake thermal efficiency improvements by friction reduction needs further investigation. This is especially so with the crankshaft bearings’ lubrication system, which can provide as much as 40% of the total mechanical losses in some cases. It is a well-established fact, that plain bearings require a minimum oil flow volume to maintain their real function rather than oil pressure. However
The use of straight vegetable oil in diesel engines leads to undesirable consequences due to the peculiar physicochemical properties of vegetable oils. In this regard, the use of pure and unmodified vegetable oils requires their obligatory dilution with petroleum fuels, usually diesel fuel. However, blends of diesel fuel with vegetable oil have a significantly higher density and viscosity than pure diesel fuels. Therefore, in this article, it was proposed to use blends of vegetable oil with aviation kerosene since kerosene has lower density and viscosity compared to diesel fuel. In addition, kerosene is less prone to coking of injectors, has a higher calorific value, and has a lighter hydrocarbon composition, which makes starting the engine easier. Within the framework of the study, engine tests of a full-size four-cylinder diesel engine, MMZ D-245.12.C, were carried out at maximum load in the range of crankshaft speeds from minimum (1000 min−1) to nominal (2400 min−1). Various blends
The automotive industry is facing a challenge as efficiency improvements are required to address the strict emission norms which in turn requires high performance downsized, lightweight IC engines. The increasing demand for lightweight engine needs high strength to weight ratio materials. To meet high strength to weight ratio, castings are preferable. However due to strength limitations for critical crankshaft applications, it forces to use costly forgings such as micro alloyed forging steel and Martensitic (after heat treatment) forging steel. To reduce the cost impact, high strength Austempered Ductile iron (ADI) casting is developed for crankshaft applications to substitute steel forgings. Austempered Ductile Iron is having an excellent mechanical properties due to aus-ferritic structure. The improved properties of developed ADI Crankshaft over steel forged crankshaft offers additional weight advantage. The ADI Crankshaft was subjected to rig test and meets the fatigue and
Conventional silencers have extensively been used to attenuate airborne pressure pulsations in the breathing system of internal combustion engines, typically at low frequencies as dictated by the crankshaft speed. With the introduction of turbocharger compressors, however, particularly those with the ported shroud recirculating casing treatment, high-frequency tones on the order of 10 kHz have become a significant contributor to noise in the induction system. The elevated frequencies promote multi-dimensional wave propagation, rendering traditional silencing design methods invalid, as well as the standard techniques to assess silencer performance. The present study features a novel high-frequency silencer designed to target blade-pass frequency (BPF) noise at the inlet of turbocharger compressors. The concept uses an acoustic straightener to promote planar wave propagation across arrays of quarter-wave resonators, achieving a broadband attenuation. The effectiveness of the silencer is
An Inline 4-cylinder engine is equipped with second-order balance shafts. When the engine is running under no-load acceleration conditions, the gear system of the balance shaft generated whine noise. In this paper, an analysis and experiment method for reducing the whine noise is presented. First, a flexible multi-body dynamic model of the engine is established, which includes shaft and casing deformation, micro-modification of the gears. Taking the measured cylinder pressure as input, the load on each gear of balance shaft gear system is calculated. In addition, the influence of tooth surface micro-modification on the meshed noise was analyzed. The results show that the dynamic meshing force between the crank gear and the shim gear is large under the original tooth surface micro-modification parameters, which is the main reason of the whine noise. The torsional vibration at the crankshaft nose and vibration acceleration at the cylinder block was measured during no-load conditions, and
Currently, there are no safe and suitable fuel sources with comparable power density to traditional combustible fuels capable of replacing Internal Combustion Engines (ICEs). For the foreseeable future, civilian and military systems are likely to be reliant on traditional combustible fuels. Hybridization of the vehicle powertrains is the most likely avenue which can reduce emissions, minimize system inefficiencies, and build more sustainable vehicle systems that support the United States Army modernization priorities. Vehicle systems may further be improved by the creation and implementation of artificial intelligence and machine learning (AI/ML) in the form of advanced predictive capabilities and more robust control policies. AI/ML requires numerous characterized and complete datasets, given the sensitive nature of military systems, such data is unlikely to be known or accessible limiting the reach to develop and deploy AI/ML to military systems. With the absence of data, AI/ML may
Although electricity is necessary for a country's economic development, many countries lack suitable grid infrastructure. Portable generators offer a consistent electric supply in the event of a blackout. Be-Rex B.V. develops and already assembled a revolutionary engine-generator prototype. It eliminates the use of camshafts, crankshafts and flywheels while integrating the generator parts into the same spherical housing. Thus, it constitutes a compact, lightweight and cost-efficient singular unit. There is no mechanical power output while the load of the engine is determined by the demanded load of the generator. The four combustion chambers are arranged in pairs on the north and south hemisphere and the magnets of the stator are placed circumferential at the equator of the spherical housing. The rotating disc and the joiner build the rotor of the generator. While developing the engine special emphasis has been put on its multi-fuel capability. Optimized gas exchange together with an
Internal combustion (IC) engines are the most common power unit technology found in road vehicles. The process of combustion within IC engines is linked to the output torque and overall powertrain performance. This work presents a method of analysing the parameters of cylinder pressure and crankshaft instantaneous speed signals obtained from a turbocharged, 4-stroke, 4-cylinder, 1.6 Litre, spark ignition, gasoline direct injection engine at various speed and load operating conditions. Whereas cepstrum analysis is used in the present work to extract critical features characterising the combustion process. Cepstrum analysis showed that the location of maximum heat release can be directly obtained from the quefrency of the instantaneous crank speed. This paper presents a systematic scheme for applying cepstrum for obtaining combustion features from the instantaneous crank speed signal.
In this work, the progressive disassembly method is used to determine the mechanical losses contributed by the different components of a single-cylinder spark ignition engine tested at crankshaft angular speeds of 300−1900 min-1, and lubricant temperatures between 30−35 °C. From the experimental measurements, the losses due to the intake and exhaust manifolds, cylinder head, valve train, camshaft bearings, connecting rod-piston assembly, flywheel, and crankshaft bearings are determined. It is obtained that the elements with the highest contribution are the piston-connecting rod assembly and the cylinder head with contributions of 19.2−36.9% and 27−33.3%, respectively. Additionally, the indicated diagram method is applied to assess the pumping, heat, and blow-by losses of the complete motored engine during the intake and exhaust processes. Pumping losses, heat and blow-by transfers, friction, and auxiliary losses are characterized, obtaining contributions between 5.8−14.7%, 14.8−37.9
The article discusses the cooperation of the elastomeric sealing ring with the shaft in terms of wear and losses to overcome frictional forces, the design of a classic seal and seals with reduced resistance to movement. Since the seal-shaft lip arrangement is a specific friction pair, the focus was on local micro-scale contact conditions as a parameter determining global macro resistance to movement. Test rig and research method was described. Friction losses were measured during the long-term tests. Thanks to the modification applied, a reduction of friction losses of 18-25% was achieved. Sealing lip profiles and shaft surface were compared before and after the test. The tests that have been carried out for two types of oils allow us to conclude that there is a need to modernize the lip seals for their long-term operation.
This SAE Standard was developed to provide a method for indicating the direction of engine rotation and numbering of engine cylinders. The document is intended for use in designing new engines to eliminate the differences which presently exist in industry.
The further increase in the efficiency of heavy-duty engines is essential in order to reduce CO2 emissions in the transport sector. This is also valid for the future use of alternative fuels, which can be CO2-neutral, but can cause higher total costs of ownership due to higher prices and limited availability. In addition to thermodynamic optimization, the reduction of mechanical losses is of great importance. In particular, there is a high potential in the piston bore interface, since continuously increasing cylinder pressures have a strong influence on the frictional and lateral piston forces. To meet these future challenges of increasing heavy-duty engine efficiency, AVL has developed a floating liner engine for heavy-duty applications based on its tried and tested passenger car floating liner concept. This article describes the concept of the friction single-cylinder engine developed to measure both the frictional forces and the lateral forces that occur between the piston assembly
A computational study based on unsteady Reynolds-Averaged-Navier-Stokes that resolves the gas-liquid interface was performed to examine the unsteady multiphase flow in a 4 cylinder Inline (i-4) engine. In this study, the rotating motion of the crankshaft and reciprocating motion of the pistons were accounted for to accurately predict the oil distribution in various parts of the engine. Three rotational speeds of the crankshaft have been examined: 1000, 2800, and 4000 rpm. Of particular interest is to examine the mechanisms governing the process of oil drawdown from the engine head into the case. The oil distributions in other parts of the engine have also been investigated to understand the overall crankcase breathing process. Results obtained show the drawdown of oil from the head into the case to be strongly dependent on the venting strategy for the foul air going out of the engine through the PCV system. Results also show the dynamic holdup of oil in the steady operation to be
Lubricating oils for automotive engines have been incorporating important improvements in chemical properties to increase engine performance, reduce fuel consumption and vehicular emissions indices, in addition to increasing the time interval for changing the lubricant itself. The objective of this study is to investigate the vibrational behavior of the block and crankshaft an Otto cycle internal combustion engine operated with ethanol and gasoline fuel as a function of the viscosity and total base number (TBN) of the lubricant. The study consisted of instrumenting the block and the 1st and 5th fixed bearings of the crankshaft with accelerometers to measure the engine vibration intensity and operating the engine on a bench dynamometer in a specific test cycle. Each experiment lasted 600 hours and every 50 hours a block and crankshaft engine vibration level were measured and 100ml sample of lubricating oil was collected to check viscosity and TBN chemical lubricant's properties. The
Three-dimensional transient numerical simulations are conducted to study the oil flow in a four-cylinder internal-combustion engine while it operates without its oil filler cap on. The emphasis of the study is on analyzing the consequential oil ejection through the oil-cap open boundary. Navier-Stokes equations are solved together with the multiphase Volume of Fluid (VOF) model and the k-ϵ turbulence model. The engine crank shaft is mechanically connected to two cam shafts through a chain, which operates below the oil-filler duct. A baffle is located between the chain and the duct, shielding the latter to minimize oil ejection and potential spills. The chain geometry and dynamics are captured accurately through volume remesh and conformal mapping techniques. The motion of the four pistons, crank shaft, and two cam shafts is also considered. Retaining all these mechanical and geometrical details in the simulations is essential to obtain accurate oil ejection results. The crank shaft
Free piston linear engines (FPLE) directly convert the piston reciprocating motion into electricity using an integrated linear alternator. Unlike conventional crankshaft engines, the FPLE’s motion is variable and is not restricted between the predefined or fixed dead centers. The variable FPLE motion is governed by the system of forces acting on the translator (reciprocating) mechanism. In some cases, energy storage devices like stiff mechanical springs are used in the FPLE system for increasing frequency and power density. Variations in the forces acting on the reciprocating mechanism will significantly influence the dynamics, in-cylinder thermodynamics, and mechanical friction losses of FPLE. While the researchers til today focused on finding the piston ring frictional characteristics for one design and operating point, no investigation was performed to understand how different design and operating variables impact the frictional characteristics of a free piston engine. Furthermore
This article proposes a new misfire detection index, the ΔGap slope, for a four-cylinder engine. However, the proposed index is not limited to four-cylinder engines. The ΔGap slope uses the tooth time measured using the existing crankshaft position sensor; therefore, an additional sensor is not required, which makes it economical. The ΔGap slope is defined as the difference between the gap slopes of the same cylinder for two adjacent cycles. Various factors that cause deviations in gap slopes between cylinders can be eliminated in the process of determining the difference between two gap slopes. Hence, in contrast with the existing engine roughness method, the ΔGap slope has the advantage of not requiring compensation for deviations between the cylinders. The conventional gap slope method must use different sets of thresholds for each cylinder located at the same position on the sensor wheel, which results in multiple thresholds being applied. In contrast, the ΔGap slope can use the
Firing order is the succession in which each cylinder is fired in a multicylinder engine. Firing order, if not properly decided, creates unbalanced moments. These unbalanced moments give rise to higher bending stresses and are also responsible for the vibrations caused. The crankshaft is the component that undergoes tensile and compressive forces due to gas pressure. Hence it is necessary to analyze the crankshaft with respect to gas forces (gas forces are decided based on firing order sequence). Considering the same as the base, an optimum firing order is selected for the Horizontal K engine. It is selected on the basis of results extracted from rigid body dynamics in ANSYS 16.0. Firing order greatly affects the strength and thermal characteristics of the crankshaft. Hence a finite element study is performed on the crankshaft for the finalized firing order. This is done to check for the stresses, deformation, and temperature contours induced in the crankshaft. ABAQUS 6.13 is used for
Small commercial vehicles (SCVs) are the drivers of a major part of India’s indirect economy, providing the most efficient means of transport. With the introduction of BS-VI norms, some major overhauls have been done to the SCV models to meet BS VI norms in challenging timeline for early market entry. This forced to automotive designers towards challenge of cost competitiveness as well as refinement level to survive in this competitive market. This paper explains the systematic approach used to overcome challenges of higher tactile vibrations, higher in-cab noise because of BS VI requirement in 2 cycle engine required for small commercial vehicle. The solutions were need to be worked out without compromising the other performance attributes like total cost of ownership, fuel economy, ease of servicing and cost effectiveness. With universal truth that for two cylinder engines with 360 degree phase crankshaft configuration, naturally aspirated common rail diesel engine, there will be
Complex FEAD system in modern powertrain is reality today due to demanding regulation, hybrid powertrain and increasing customer expectation. Gasoline engines are going to be preferred over diesel engines specially for passenger car application. These downsized engines lead to increase engine excitation and so to higher dynamics. Use of overrunning alternator pulley (OAP) is globally accepted as cost effective and technically proven product for FEAD system to make it robust by optimizing the system performance such as belt tension, hub load, slippage and vibrations to improve fuel consumption and to reduce engine emissions. OAP is a mechanical device with one-way clutch unit which eliminates the torsional vibrations coming from engine crankshaft and ensures only accelerating proportions of crankshaft forces are transferred to alternator which means reduction in force level of belt drive system. This paper describes the advantage of usage of OAP to achieve reduction in fuel consumption
Because of ever increasing demand for more fuel efficient engines with lower manufacturing cost, compact design and lower maintenance cost, OEM’s prefer three cylinder internal combustion engine over four cylinder engine for same capacity, though customer demands NVH characteristics of a three cylinder engines to be in line with four cylinder engine. Crank-train balancing plays most vital role in NVH aspects of three cylinder engines. A three cylinder engine crankshaft with phase angle of 120 degrees poses a challenge in balancing the crank train. In three-cylinder engines, total sum of unbalanced inertia forces occurring in each cylinder will be counterbalanced among each other. However, parts of inertia forces generated at No.1 and No. 3 cylinders will cause primary and secondary resultant moments about No. 2 cylinder. Conventional method of designing a dynamically balanced crank train is time consuming and leads to rework during manufacturing. Also, different vehicle models with a
This work investigates the development of a novel series hybrid architecture utilizing a single cylinder opposed piston engine. The opposed piston engine presents unique benefits in a hybrid architecture such as its lower heat transfer due to a favorable surface area to volume ratio and lack of a cylinder head, as well as the thermodynamic benefits of two stroke operation with uniflow scavenging. A particular focus of this effort is the work extraction efficiency of two design concepts. The first design concept utilizes a geartrain to couple the crankshafts of the engine in a conventional manner, providing a single power take-off for coupling to an electric motor/generator. In this design, the large inertia of the geartrain dampens the speed fluctuation of the single cylinder engine, reducing the peak torque required to for the electric machine. However, the friction losses caused by the geartrain limit the maximum work extraction efficiency. The second design concept eliminates the
In this work, a novel opposed piston architecture is proposed where one crankshaft rotates at twice the speed of the other. This results in one piston creating a 2-stroke profile and another with a 4-stroke profile. In this configuration, the slower piston operates in the 2-stroke CAD domain, while the faster piston completes 2 reciprocating cycles in the same amount of time (4-stroke). The key benefit of this cycle is that the 4-stroke piston increases the rate of compression and expansion (dV/dθ), which lowers the combustion-induced pressure rise rate after top dead center (crank angle location of minimum volume). Additionally, it lowers in-cylinder temperatures and pressures more rapidly, resulting in a lower residence time at high temperatures, which reduces residence time for thermal NOx formation and reduces the temperature differential between the gas and the wall, thereby reducing heat transfer. In this work, a custom 0D thermodynamic model was used to study the sensitivity of
For any combustion engine, balance has always been important regardless of types of cylinder layout. One of the disadvantages of the inline four engines is the second-order unbalanced forces, which leads to high-frequency excitation of vehicle’s structure and consequent internal noise. Balance shaft modules (BSM) are often used in inline-four engines, to reduce the second-order vibration and mitigate engine imbalance. Balance shafts are often running at light load and high-speed condition which could induce both gear rattle and gear whine from the BSM gear set. Typically, scissor gear set is used between crankshaft and BSM to reduce the gear rattle noise. However, a poor scissor gear design could easily lead to unpleasant gear whine noise. There is an increasing trend to shorten development cycles and reduce cost using simulation models. This paper discusses an analytical method to simulate gear whine and rattle generated by engine BSM. Simulation software MASTA is a robust and fast
Two-layer engine front end accessory drive systems (TEFEADS) are adopted generally by commercial vehicles due to the characteristics of the accessory pulleys, which have large torque and moment of inertia. An overrunning alternator decoupler (OAD) is an advanced vibration isolator which can reduce the amplitude of torsional vibration of alternator rotor effectively by an one-way transmission and they are more and more widely used in vehicles. This paper established a model of a generic layout of a TEFEADS with an OAD. The coupling effect between the TEFEADS, the nonlinear characteristics of OAD, the torsional vibration of crankshaft and the creeping on the belt were taken into account. A nine pulleys model was provided as a study example, the dynamic responses, which are respectively under steady and accelerating conditions, of the system were calculated by the established method and compared with the bench experiment. The influence of different belt material, the stiffness of OAD
With the modernization of the technology, significant emphasis has been given to weight reduction in the number of engine components. This change is predominantly governed by the introduction of composites and ceramics. The crankshaft is an important part of an IC engine that converts the reciprocating motion of the piston into rotary motion through the connecting rod. This paper is focused on the weight optimization of the crankshaft by analyzing it for different stresses and dynamics loads using different materials viz. AISI 4340, Al B4C, AISI 4330M, 42-CrMo-4, AISI 6061-T6, and Aluminum alloy. Computational study of the different candidate materials for the crankshaft is done using an inline 4-cylinder diesel engine. A standard 3D model of the crankshaft is made using DS Solid works 2013 software and the computational analysis is being carried out using Ansys Workbench. The study focuses on decreasing the weight of the crankshaft while maintaining not much alteration to induced
In recent years, the supercharged spark ignition engine (SI engine) is spread out in the field of passenger vehicle. However, it has a problem of abnormal combustion which is called Low Speed Pre-ignition (LSPI). It is cleared gradually that the character of lubricating oil effects on LSPI. The lubricating oil which has a tolerance for LSPI has been introduced already in the market nowadays. However, cause and mechanism of LSPI occurrence does not clear sufficiently. In previous conference SETC 2018, it was reported that the peculiar behavior of LSPI corresponded with behavior of lubricating oil from piston crown [1, 2, 3]. This paper focuses on frequency of lubricating oil scattering from piston crown. The behavior of lubricating oil from piston crown has four steps as follows, firstly, lubricating oil goes up along with piston side toward piston crown. Secondly, lubricating oil which reaches piston crown continues to accumulate against reciprocating motion. Thirdly, accumulated
Two new misfire detection indexes for single-cylinder motorcycle engines—dubbed gap distance (GD) and gap slope (GS)—are proposed in this study. GD and GS quantify the change in engine angular acceleration using the tooth time measured by the crankshaft position sensor (CKPS). GD is defined as the product of the spacing distance I (the distance from the top dead center at the explosion stroke [TDC2] to the engine speed trend line parallel to the engine speed axis) and spacing distance II (the distance from the bottom dead center at the expansion stroke [BDC2] to the engine speed trend line parallel to the engine speed axis). GS is defined as the difference between the two slopes between the engine speed inclination line and the engine speed trend line. Here the engine speed trend line connects two engine speeds at the top dead center at the intake stroke (TDC1) of the current and subsequent cycles. The GD and GS indexes can detect misfires using the engine speeds at only four teeth
This article presents a misfire detection index for motorcycles with a single-cylinder engine. Compared with automobiles with multicylinder engines, attempts to diagnose single-cylinder motorcycle engine misfires have been rare. Therefore, a new index, detrended engine rpm amplitude (DERA), is proposed to detect misfires using tooth time measured by the crankshaft position sensor; thus, there is no additional cost for the DERA index. This index is defined as the difference between the squares of the maximum and minimum values of engine speed (rpm) detrended by the engine speed trend line, instead of the linear regression method. Thus calculating the DERA index becomes simple and fast, and it is advantageous to reduce the computation time. Here the engine speed trend line is a line connecting the engine speeds at the first teeth of the current and subsequent cycles. The analysis of the optimal threshold for detecting misfires reveals that DERA yields a good misfire detection rate of
This SAE Standard specifies the major dimensions and tolerances for Engine Flywheel Housings and the Mating Transmission Housing Flanges. It also locates the crankshaft flange face or the transmission pilot bore (or pilot bearing bore) stop face in relation to housing SAE flange face. This document is not intended to cover the design of the flywheel housing face mating with the engine crankcase rear face or the design of housing walls and ribs. Housing strength analysis and the selection of housing materials are also excluded. This document applies to any internal combustion engine which can utilize SAE No. 6 through SAE No. 00 size flywheel housing for mounting a transmission.
Currently automotive design is facing multi facet challenges such as reduction in greenhouse gases, better thermal management, and low cost solution to market, vehicle weight management etc. Considering these challenges, efforts had been taken to improve weight management of engine while optimizing the cost of it. Good ‘engine breathing’ is usually associated with efficient intake system e.g. high flow air filter, a well-designed manifold, cylinder block, cylinder head and cylinder head cover etc. However, efficient ‘crankcase breathing’ is an equally important function of any engine. Even in a new engine, the combustion pressure will inevitably pass the piston rings into the crankcase. If an engine’s breathing system should become blocked or restricted, the crankcase will pressurize causing lots of problems to the engine. Prior to 1963 most vehicle engines vented their vapors and oil deposits to atmosphere and the road surface. With increasing environmental pressures positive
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