Browse Topic: Crankshafts
A computational investigation was carried out using SimericsMP+ to analyze oil distribution and aeration behavior in a V6 engine oil pan during severe vehicle maneuvers. The model accounted for the crankshaft/camshaft rotations and piston motions, which allows for capturing realistic oil distribution in cylinder head drainbacks, engine bay and sump after initializing the crankcase with prescribed oil levels to establish baseline aeration prior to applying dynamic maneuver profiles. Of particular interest was the response of the main oil gallery (MOG) pressure and the exposure of the oil pickup tube during kickoff conditions at multiple fill levels. Both a baseline configuration and a modified sump featuring a containment “doghouse” were examined. Results obtained from the kickoff maneuver show complete uncovering of the pickup tube in the baseline design, leading to unstable lubrication. The first doghouse design only delayed pickup tube uncovering briefly, as oil pooled at the rear gap and air ingestion still occurred. Full fill avoids air ingestion; however, high interaction with the crank shaft results in higher oil aeration longer term after kickoff maneuver ends. The findings highlight the complexity of oil behavior in engine environments, where unpredictable interactions during dynamic maneuvers can easily lead to ingestion and aeration. Despite this complexity, the computational strategy developed in this study was able to accurately reproduce and predict these events which were seen in the test scenario as well in the form of pressure readings at the pump inlet. Since these high-aeration events were validated against experimental measurements, this simulation approach proves to be highly valuable for guiding product design and optimization, allowing engineers to identify risks early and improve lubrication performance in the engines before physical testing.
Condition-based monitoring (CBM) has emerged as a transformative approach in predictive maintenance, enabling the proactive identification of potential component failures. It offers numerous advantages like Cost Savings, Increased Equipment Lifespan, RCA of failed parts, Optimized Resource Utilization, Reduced Disruptions, Enhanced Reliability and Safety and many more making it a vital approach for effective maintenance and operational efficiency. This paper presents a comprehensive methodology for monitoring and analyzing vibration trends to predict and prevent the breakdown of critical components in IC Engine in its testing phase. The good part here is that this methodology is not just limited to IC Engine but can be applied across wide range of industries and mechanical systems as from the literature and past vibration data, it was observed that before any such failure engine vibration increases. If the engine is stopped at that moment, it can be preserved, allowing for further investigation to be conducted. During the engine reliability development process, failures in the crank train and valve train can result in damage to multiple components, making it challenging to analyze the sequence of failure and identify the initial cause and root problem. By employing advanced vibration analysis techniques, the study aims to detect anomalies indicative of wear, misalignment, or other precursors to failure. This research contributes to the growing body of knowledge in CBM, offering a scalable and adaptable framework for implementing vibration-based predictive maintenance across diverse industrial applications. The proposed methodology not only enhances reliability but also supports sustainable maintenance practices by minimizing resource wastage and ensuring timely interventions.
In this article we examine the behavior of oil in the lubrication channel between the main bearing and the connecting rod bearing in the crankshaft of an internal combustion engine. The requirement for high service life and proper operation of these bearings, while minimizing input power of the lubrication system, lead to the need to understand the function of these structural parts in detail. To simulate and visualize this process, an experimental device was created. The device allows the experimenters to change individual parameters such as rotation speed, oil pressure, oil temperature, and aeration, while simultaneously visualizing the process with the help of a special rotating camera. These parameters are then obtained by image processing. In this way, the following influences are investigated here: at oil temperatures of 30, 50, and 80°C, relative oil pressures of 1, 2, 3, and 4 bar, at undissolved air in the oil of 5 and 10 vol% and crankshaft station speeds from 0 to 6000 1/min. The work is inspired by previously known publications by other authors. Their results were obtained mainly using computational methods. In the case of experiments, the authors used indirect methods of measurement using pressures and flows. Therefore, this work has a great contribution in the experimental area. The results of the experiments show the influence of the tested parameters on the gradual limitation of the oil flow through the channel. At a relative oil pressure of 1 bar and a crankshaft speed of 6000 1/min, the pressure even drops to 0 bar, and the oil flow through the channel collapses. The results of image processing show not only the area of the channel filled with oil, but also the distance of the beginning and end of the air bubble from the beginning of the channel.
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 Frequency Response Function (FRF) were carried out to identify the mode shapes and resonant frequencies. Vibration on WP housing were compared with Fan engaged and disengaged condition to identify the critical frequency ranges that minimize vibrational impacts on the WP housing. The results indicate a significant correlation between Fan Blade Pass Frequency (FBPF) and vibrational amplitude on WP housing. By optimizing FBPF, it is successfully mitigated high vibration levels, thereby enhancing the structural integrity and operational reliability of the WP housing. In addition, the results of crack initiation points, strain gauge measurements, structural and modal analyses are examined to enhance the WP housing strength.
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 still be developed and deployed to military systems if supported by near-real-time or real-time computationally efficient and effective hardware and software or cloud-based computing. In this research, an OPAL real-time (OPAL-RT) simulator was used to emulate a compression ignition (CI) engine simulation architecture capable of developing and deploying advanced AI/ML predictive algorithms. The simulation architecture could be used for developing online predictive capabilities required to maximize the effectiveness or efficiency of a vehicle. The architecture includes a real-time simulator (RTS), a host PC, and a secondary PC. The RTS simulates a crank angle resolved engine model which utilized pseudo engine dynamometer data in the form of multi-dimensional matrices to emulate quasi-steady state conditions of the engine. The host PC was used to monitor and control the engine while the secondary PC was used to train the AI/ML to predict the per-cylinder generated torque from the crank shaft torque, which was then used to predict the in-cylinder temperature and pressure. The results indicate that using minimal sensor data and pretrained predictive algorithms, in-cylinder characterizations for unobserved engine variables may be achievable, providing an approximate characterization of quasi-steady state in-cylinder conditions.
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 the finite element method (FEM).
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 and emissions, to make the FEAD system efficient over the rigid alternator pulley by eliminating the rotational irregularities coming from FEAD system. In this paper, various engine driving conditions have been simulated to assess FEAD system performance in terms of hub load, belt pre-tension, belt slippage and vibrations by comparing rigid pulley and overrunning alternator pulley, followed by engine validation, which shows effectiveness of OAP.
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 same engine can call for different crank-train options resulting in increased development time and efforts. This paper discusses a numerical and digital approach for designing crank train of a three cylinder gasoline engine with dynamically balanced for any option required by vehicle. This approach eliminates the iterative process of prototyping. Multibody dynamic model of 1200 cc three cylinder gasoline engine crank train is developed with inertia properties of all child parts including crankshaft, piston and connecting rod. Reciprocating and rotating inertia forces with their moments were considered for respective child parts. Reasonable tolerances to achieve desired static and dynamic balance in production parts were determined by this approach. A sensitivity study to understand influence of counterweights on crankshaft balancing is also performed using this approach. All values and correlations developed in this approach are validated on physical engines.
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