Browse Topic: Crankshafts
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
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
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.
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
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
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
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
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.
Piston is the most imperative part of an automotive engine in which it exchanges drive due to expanding gas in the cylinder to the crankshaft through the piston rod. During the combustion of fuel charge inside the ignition chamber, high pressure and temperature are developed and the piston is imperiled to high mechanical and thermal stresses. The main objective of the proposed work is to analyse the stress distributions and thermal behaviour of uncoated A356 with 5wt% SiC and 10wt% Fly Ash HMMC piston crown and Plasma sprayed Yttrium Stabilized Zirconia (Y-PSZ) coated A356 with 5wt% SiC and 10wt% Fly Ash HMMC piston crown. A356 with 5wt% SiC and 10wt% Fly Ash HMMC were fabricated via squeeze casting to improve the performance of a petrol engine. A structural model of an HMMC piston crown was made using CREO software and structural and thermal analysis was done using ANSYS. Further coupled field analysis is done to find the stress and temperature distribution on the piston. Output
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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