Criteria

Text:
Display:

Results

Viewing 91 to 120 of 6706
2016-09-18
Technical Paper
2016-01-1957
Seonho Lee, Heejae Kang, Ohchul Kwon, Chirl Soo Shin
Abstract A trend in automotive parts development is the pursuit of long life, high quality and reliability. The increase in service life of automotive wheel bearings, by improving the rolling contact fatigue (RCF) life of bearing steels, was investigated. Conventional studies of bearing steels and heat treatments have dealt with quenching and tempering (Q/T) in 52100 steel. This study is a new trial to increase the strength of bearing steels by special austempering in phases after general Q/T heat treatments.
2016-09-18
Journal Article
2016-01-1959
Laura Sguotti, Davide Olivieri, Domenico Bosco
Abstract Bearing friction is a direct contribution to vehicle CO2 emissions. The friction is defined as the total resistance to rotation, resulting from the combination of rolling and sliding friction in the contact areas. First, friction reduction was approached from a theoretical standpoint by employing modeling and simulation techniques. Improvements identified in simulation were then used to: create a new set of design rules for the internal geometry of the bearing, introduce a new grease, develop new seals, also with the integration of labyrinth functions and an optimization of the preload range variation. In order to provide a reliable confirmation of the expected achievements, a new friction measurement methodology was also introduced.
2016-09-18
Journal Article
2016-01-1958
Seungpyo Lee, Nahyon Lee, Jongkeun Lim, Jungyang Park
Abstract Through transmitting power and carrying vehicle weight, automotive wheel bearings play an important role. Counterbalancing the bearing responsibilities, they also are designed to last the life of a vehicle without servicing. When mounted to the vehicle steering knuckle by bolts, distortion occurs to the outer ring. Performance is affected when distortion takes place at the seal mounting location and raceways. Finite element analysis using commercial software was performed to analyze the outer ring distortion. Elasto-plastic and contact analyses were carried out to compute the clamping behavior of the outer ring, bolts and the knuckle under various conditions. To verify the reliability of this study, the distortion of the outer ring was measured. The experimental results proved to be comparative with the analysis results.
2016-09-18
Journal Article
2016-01-1956
Robert G. Sutherlin, Douglas Reed
Abstract For higher mileage vehicles, noise from contaminant ingress is one of the largest durability issues for wheel bearings. The mileage that wheel bearing sealing issues increase can vary due to multiple factors, such as the level of corrosion for the vehicle and the mating components around the wheel bearing. In general, sealing issues increase after 20,000 to 30,000 km. Protecting the seals from splash is a key step in extending bearing life. Benchmarking has shown a variety of different brake corner designs to protect the bearing from splash. This report examines the effect of factors from different designs, such as the radial gap between constant velocity joint (CVJ) slinger and the knuckle, knuckle labyrinth height and varying slinger designs to minimize the amount of splash to the bearing inboard seal. This report reviews some of the bearing seal failure modes caused by splash.
2016-09-18
Technical Paper
2016-01-1960
Yukihisa Takayama
Recently, vehicle production volumes have been increasing, particularly in newly developing countries that often lack adequate infrastructure. These regions utilize many unimproved roads and frequently experience heavy rainfall, requiring robust product features. In contrast, developed countries, with well-maintained infrastructure, have emphasized protection of the environment, requiring automobile manufacturers to target reductions in carbon dioxide emissions. Hub unit bearings, which enable smooth wheel rotation, are mounted at the wheel center. The hub bearing is a critical part which supports the automotive body and requires high reliability. To make environmental progress, hub unit bearings have increasing requirements for low friction. NSK has developed effective grease technologies to meet the diverse requirements of hub unit bearings, such as high reliability and low friction under severe environmental conditions.
2016-06-15
Technical Paper
2016-01-1818
Raimo Kabral, Lin Du, Mats Abom, Magnus Knutsson
Abstract The concept of IC engine downsizing is a well-adapted industry standard, enabling better fuel conversion efficiency and the reduction of tailpipe emissions. This is achieved by utilizing different type of superchargers. As a consequence, the additional charger noise emission, at the IC engine inlet, can become a problem. In order to address such problem, the authors of this work have recently proposed a novel dissipative silencer for effective and robust noise control of the compressor. Essentially, it realizes an optimal flow channel impedance, referred to as the Cremer impedance. This is achieved by means of a straight flow channel with a locally reacting wall consisting of air cavities covered by an acoustic resistance, e.g., a micro-perforated panel (MPP). In this paper, an improved optimization method of this silencer is presented. The classical Cremer impedance model is modified to account for mean flow dependence of the optimal wave number.
2016-06-15
Technical Paper
2016-01-1763
Thierry Bourdon, Rodrigue Bouete
Abstract Either from a legislative point of view or because of OEM demands, the automotive industry is increasingly facing of reducing vibration & noise in the vehicle. More particularly on the engine area, the development of Gasoline and Diesel fuel components based on high pressure pumps, rails, any pipes and injectors are more and more subject of a particular NVH (Noise Vibration and Harshness) attention. The use of modern digital techniques such as 3D FEM vibroacoustic, leads to use virtual prototyping as complementary to traditional real hardware prototypes development. Among interest, number of iterative loops to reach a best design brings an important value to new product development with an optimized cost. Basically the core part of virtual prototyping is about a 3D FEM model definition for each component.
2016-06-15
Technical Paper
2016-01-1856
Hannes Allmaier, Günter Offner
Abstract Elastohydrodynamic (EHD)-simulation is a widely applied simulation technique that is used in a very diverse field of applications ranging from the study of vibroacoustics to the calculation of friction power losses in lubricated contacts. In particular, but not limited to, the automotive industry, technical advances and new requirements put current EHD simulation methodology under test. Ongoing trends like downsizing, downspeeding, start-stop and the continuing demand for increasing fuel efficiency impose new demands and challenges also on the simulation methodology. Increasing computational capabilities enable new simulation opportunities on the other hand. In the following, an overview is given on the current state of the art and today’s challenges for the elastohydrodynamic simulation of journal bearings and their wide range of applications from highly loaded main bearings supporting the crank shaft in the ICE to high speed turbocharger bearings.
2016-04-05
Technical Paper
2016-01-0011
Salah Alhasia, Sharif Gindy, Badih Jawad, Chris Riedel, Selin Arslan
Abstract Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. In high speed applications, rolling element forces and gyroscopic moments can be significantly high compared to the applied forces acting on a bearing. Such moments create a “driving” torque causing outer race to creep. In this paper a mathematical model for the dynamics of a rolling element in a high speed bearing is derived. Preload values counterbalancing the torque driving the outer race to rotate can be predicted from this model. An attempt to experimentally measure this torque using a specially designed apparatus with integrated strain gauge torque sensor is also described. Both model and experimental measurements are aimed at understanding, and therefore preventing bearing failures due to outer race (creep) rotations.
2016-04-05
Technical Paper
2016-01-0107
Sjon Moore
Abstract Traditional methods of costing wire harnesses focus primarily on the material and labor costs for manufacturing the final product. Rarely are costs related to variation-based complexity considered and when they are they tend to be simple approximations at best. In reality, the additional costs of excessive variation resulting in large part counts (unique harness level part numbers) can have a significant impact on the final cost incurred by an organization, and is often difficult to account for making it impossible for an organization to optimize their design, and everything that goes into making and delivering a finished product. It's important that these costs first be understood and modeled, and second that the designs be optimized based on this model. This paper will discuss these complexity based costs, including common sources, how they can be modeled, and methods for optimizing designs to account for these costs.
2016-04-05
Technical Paper
2016-01-0448
Yuliang Yang, Yu Yang, Ying Sun, Zhihong Dong, Yunquan Zhang
Abstract To improve the vehicle NVH performance and reduce the vibration of the exhaust system, average driving DOF displacement (ADDOFD) and dynamic analysis are used to optimize hanger locations. Based on the finite element model and rigid-flexible coupling model, exhaust system analysis model was established. According to the finite element model of the exhaust system, the free-free modal analysis is carried out, and the position of the hanging point of the exhaust system is optimized by using the ADDOFD method. Furthermore, through the dynamics analysis, the force of each hanger to the body is calculated by the dynamic analysis, then verify the rationality of the hanging position. The combination of the two methods can effectively determine the better NVH performance of the exhaust system with hanger locations in the earlier vehicle development process.
2016-04-05
Technical Paper
2016-01-0512
Chae-Hwan Hong
Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the PLA composites including stereocomplexed with L- and D-PLA, we developed the unit processes such as fermentation, separation, lactide conversion, and polymerization. We investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time of lactide synthesis step. Poly(d-lactide) is obtained from the ring-opening polymerization of d-lactide. Also we investigated several catalysts and polymerization conditions.
2016-04-05
Technical Paper
2016-01-0511
Na Qiu, Yunkai Gao, Jianguang Fang, Shanshan Wang
Abstract As a potential material for lightweight vehicle, polymethyl methacrylate (PMMA) has proven to perform well in optical behavior and weather resistance. However, the application in automotive glazing has seldom been studied. This paper investigates the defrost performance of PMMA rear window using both numerical and experimental methods. The finite element analysis (FEA) results were found to be in good agreement with the experimental data. Based on the validated finite element model, we further optimized the defrost efficiency by changing the arrangement of heating lines. The results demonstrated the frost layer on the vision-related region of PMMA rear window can melt within 30 minutes, which meets the requirement of defrost efficiency.
2016-04-05
Technical Paper
2016-01-0391
Tanmay Sushant Santra, Vikas Kumar Agarwal, Mihir Bhambri
This paper depict the difference in the endurance factor of safety with usage of static and quasi static FE analysis and corrective measures take to solve the problem. The importance of the dynamic loading and subsequent effect of it on the multi axial fatigue analysis. Considering the modern trend prevailing among the vehicle manufacturers and specifically talking about two wheeler industry, it is clear that while the engine remains the same but the frame is changed to cater the market with new models to cut down on the development time. Initially the crankcase was designed for a double cradle frame where the crankcase was mounted on the frame. Later, the frame design was changed to single cradle where engine acts as a stress member link. This kind of arrangement makes the crankcase mountings participate in the chassis loads. Therefore, the crankcase mounting experiences road loads when the vehicle encounter the road irregularities.
2016-04-05
Technical Paper
2016-01-0372
Thomas Thesing, Neil Bishop
Abstract Conventional approaches for the fatigue life evaluation of automotive parts like headlamps involves the evaluation of random stress conditions in either the time or frequency domain. If one is working in the frequency domain the fatigue life can be evaluated using one of the available methods like the Rayleigh (Narrow Band) approach or the more recent Dirlik method. Historically, the random stresses needed as input to these methods have been evaluated by the FEA solver (eg Abaqus, or Nastran) and these “in built” stress evaluations have limitations which relate to the fact that the stress conditions are complex and so the common “equivalents” for stress like von-Mises or Principal have not been available. There have also been limitations in the location and method of averaging for such stresses. In addition, the fatigue calculation approach for doing the evaluation has been constrained to the linear stress based (S-N) method.
2016-04-05
Technical Paper
2016-01-0247
Jiu Xu, Predrag Hrnjak
Abstract Automotive air conditioning compressor produces an annular-mist flow consisting of gas-phase refrigerant flow with oil film and oil droplets. This paper reports a method to calculate the oil retention and oil circulation ratio based on oil film thickness, wave speed, oil droplet size, oil droplet speed, and mass flow rate. Oil flow parameters are measured by high-speed camera capture and video processing in a non-invasive way. The estimated oil retention and oil circulation ratio results are compared quantitatively with the measurements from system experiments under different compressor outlet gas superficial velocity. The agreement between video result and sampling measurement shows that this method can be applied in other annular-mist flow analysis. It is also shown that most of the oil exists in film from the mass point of view while oil droplets contributes more to the oil mass flow rate because they travel in a much higher speed.
2016-04-05
Technical Paper
2016-01-0093
Haizhen Liu, Rui He, Jian Wu, Wenlong Sun, Bing Zhu
Abstract With the development of modern vehicle chassis control systems, such as Anti-Lock Brake System (ABS), Acceleration Slip Regulation (ASR), Electronic Stability Control (ESC), and Regenerative Braking System (RBS) for EVs, etc., there comes a new requirement for the vehicle brake system that is the precise control of the wheel brake pressure. The Electro-Hydraulic Brake system (EHB), which owns an ability to adjust four wheels’ brake pressure independently, can be a good match with these systems. However, the traditional control logic of EHB is based on the PWM (Pulse-Width Modulation), which has a low control accuracy of linear electromagnetic valves. Therefore, this paper presents a research of the linear electro-magnetic valve characteristic analysis, and proposes a precise pressure control algorithm of the EHB system with a feed forward and a PID control of linear electro-magnetic valves.
2016-04-05
Technical Paper
2016-01-0031
Wenxu Niu, Ke Song, Yucheng He, Tong Zhang
Abstract X-in-the-loop (XiL) framework is a new validation concept for vehicle product development, which integrates different virtual and physical components to improve the development efficiency. With XiL platform the requirements of reproducible test, optimization and validation, in which hardware, equipment and test objects are located in different places, could be realized. In the view of different location and communication form of hardware, equipment and test objects, time delay problem exists in the XiL platform, which could have a negative impact on development and validation process. In this paper, a simulation system of time delay prediction and compensation is founded with the help of BP neural network and RBF neural network. With this simulation system the effect of time delay in a vehicle dynamic model as well as tests of geographically distributed vehicle powertrain system is improved during the validation process.
2016-04-05
Technical Paper
2016-01-0510
Praveen Mishra, Subramanian Ganeshan
Abstract An automobile outer rear view mirror (ORVM) is fixed at the front exterior of the vehicle for helping the driver see areas behind and sides of the vehicle which are outside of their peripheral vision. Mirror Scalp is the cover which protects the components inside from human and other environmental damage. Hence the scalp must be properly designed and fitted to the rest of the assembly so that it allows the safe functioning of the ORVM, which is an active safety device. During automatic car washing, sometimes the scalp may get removed due to the huge force exerted by the scrubber, if the scalp is not fitted properly. Mirror scalp is fitted to the rest of the ORVM through snap-fits. Snap-fits are the simplest, quickest and most cost effective method of assembling two parts. When designed properly, parts with they can be assembled and disassembled numerous times without any adverse effect on the assembly and hence are most environmentally friendly.
2016-04-05
Technical Paper
2016-01-0473
Muthukumar Arunachalam, S Arunkumar, PraveenKumar Sampath, Abdul Haiyum, Beverly Katz
Abstract Current generation passenger vehicles are built with several electronic sensors and modules which are required for the functioning of passive safety systems. These sensors and modules are mounted on the vehicle body at locations chosen to meet safety functionality requirements. They are mounted on pillars or even directly on panels based on specific packaging requirements. The body panel or pillar poses local structural resonances and its dynamic behavior can directly affect the functioning of these sensors and modules. Hence a specific inertance performance level at the mounting locations is required for the proper functioning of those sensors and modules. Drive point modal frequency response function (FRF) analysis, at full vehicle model for the frequency range up to 1000 Hz, is performed using finite element method (FEM) and verified against the target level along with test correlation.
2016-04-05
Technical Paper
2016-01-1014.01
Shyam K. Menon, Himakar Ganti, Chris Hagen
RETRACTED: Natural gas is an attractive option for transportation applications in the United States due to its abundant availability and potential for reduced emissions. The scarcity of refueling resources imposes a barrier to widespread use of natural gas in internal combustion engines. A novel bi-modal engine under development is capable of operating in a compressor mode and provide refueling capabilities without any supplemental devices thus overcoming the infrastructure based limitations. As part of this development, a multi-cylinder production engine was acquired and the intake modified on one of the cylinders to perform air compression. This system was tested with accompanying plate heat exchangers that allow for cooling of the compressed air. To make the system self-contained, engine coolant and vehicle refrigerant are used as heat sinks in the heat exchangers.
2016-04-05
Technical Paper
2016-01-0496
Leonardo Farfan-Cabrera, Ezequiel A. Gallardo
Abstract Debris are progressively generated just after wear occurred by the interaction of various mechanical elements inside the engines, steering gear boxes, transmissions, differentials, etc. Besides, debris could interfere with the normal operation of such components generating even more damage in other parts due to three-body abrasion. Hence, dynamic seals are susceptible to interact with very fine debris accumulated in the working lubes. Recently, owing to many test advantages, the micro-scale abrasion test has been extensively used to reproduce three-body abrasion in hard materials, coatings, polymers, etc., however, it has not been before employed for the wear assessment of elastomeric materials. This paper presents an adaptation of the micro-scale test method to study three-body abrasive behavior of an elastomeric dynamic seal (samples extracted from an automotive commercial Acrylonitrile-butadiene NBR rotary seal) under lubricated conditions.
2016-04-05
Technical Paper
2016-01-1071
Sangchul Lee, SeongMin Park, Changsun Hwang
Abstract A low pressure exhaust gas recirculation system (LP EGR system) enables the expansion of the EGR operating area than that of the widely used high pressure EGR system. As a result, fuel consumption and emissions can be improved. In order to meet the EU 5 emissions regulations, an exhaust throttle LP EGR system was used. The EU5 vehicles developed using this system have greater merits than other vehicles. However, because the exhaust throttle LP EGR valve is installed adjacent to the after-treatment system, the material of the LP EGR valve itself must be stainless steel in order to withstand the thermal stress, consequently, the cost is increased. Therefore, in order to achieve cost rationalization for EU6 vehicles, an intake throttle LP EGR system is developed and applied to replace the exhaust throttle LP EGR system. In order to apply the intake throttle LP EGR system, the EGR valve is installed in front of the turbo charger compressor.
2016-04-05
Technical Paper
2016-01-1037
Lars Eriksson, Vaheed Nezhadali, Conny Andersson
Modelbased systems engineering is becoming an important tool when meeting the challenges of developing the complex future vehicles that fulfill the customers and legislators ever increasing demands for reduced pollutants and fuel consumption. To be able to work systematically and efficiently it is desirable to have a library of components that can be adjusted and adapted to each new situation. Turbocharged engines are complex and the compressor model serves as an in-depth example of how a library can be designed, incorporating the basic physics and allowing fine tuning as more information becomes available. A major part of the paper is the summary and compilation of a set of rules of thumb for compressor map extrapolation. The considerations discussed are extrapolation to surge, extrapolation to restriction region, and extrapolation out to choking.
2016-04-05
Technical Paper
2016-01-1054
Jorge Martins, Carlos Pereira, F.P. Brito
Abstract One way to increase efficiency and performance of 2-stroke engines is the addition of an exhaust valve to control the opening/closure of the exhaust port. With this implementation it is possible to change the exhaust timing for different conditions. However, conventional systems cannot change the exhaust opening and closure timings independently. The work herein presented shows the development of a new exhaust rotary valve enabling the control of the opening independently from the control of the closure of the exhaust port. The study is based on kinetic and thermodynamic analysis. Some manufacturers use exhaust rotary valves but none of them performs a fully rotary motion. This kind of motion has various benefits such as smoothness and most notably the ability to control both the opening and the closure timing of the exhaust independently. Regarding the kinematic analysis, a simple model was created to determine the most suitable valve angles.
2016-04-05
Technical Paper
2016-01-1092
Gabriela Achtenova, Jiri Pakosta
Abstract In the laboratories of CTU in Prague, an inertia test stand was recently built for endurance tests of the internal shift mechanisms of passenger cars. With regard to the instrumentation of the stand, it can be used also for determination of lost power of the not-loaded transmission. In this paper we present the values for the no-load losses measured during different conditions (temperature, shifted speed, speed of rotation) on the automotive mechanical gearbox for the transversal disposition of the drivetrain. For the further usage of the measured values is important to determine the proportion of the different sources of losses. We are mainly interested to identify the proportion of the churning losses and losses in the sealing, since these two losses remain the same, whatever the load of the gearbox will be. The losses of bearings on input and secondary shaft were calculated with the tool available from SKF.
2016-04-05
Technical Paper
2016-01-1130
Mike Johns, Heinz Kamping, Kristian Krueger, James Mynderse, Chris Riedel
Abstract Tapered roller bearings used to support pinion and differential gears in automotive drive axles perform best with accurate assembled preload. One of the most common high volume production assembly methods relies on bearing friction to adjust preload; however torque is an indirect measure of load, can be influenced by the raceway condition, and is difficult to control. A new method to measure preload utilizes frequency response to estimate axial preload from system stiffness. The stiffness can be measured dynamically and an assembly method automated to set preload without the need for torque or dimensional measurements. By eliminating the need for a torque signal, the raceway conditions which contribute to setting torque do not contribute to the preload setting accuracy. This study demonstrates the effectiveness of using frequency response to measure stiffness and estimate preload.
2016-04-05
Technical Paper
2016-01-1311
Tsuyoshi Kanuma, Katsumi Endo, Fumiaki Maruoka, Hiroshi Iijima, Makoto Kawamura, Keisuke Nakazawa, Eiki Yanagawa
Abstract 1 The vane-type rotary compressor of a heating, ventilating, and air conditioning system (HVAC system) is simple and compact but may emit noise due to the collision between the vanes and the cylinder wall. Several studies have been conducted on this chattering noise, with a focus on the noise associated with the compressor revolution speed, temperature, suction pressure, and exhaust pressure. However, such investigations are not sufficient to reveal the behavior of the vane movement in its entirety. To minimize the chattering noise, the details of the mechanism of such vane-operating noise must be investigated by analyzing the behavior of the vanes as a function of time. The vanes move according to the balance between the front and rear pressures. This report describes a novel visualization technique with which to monitor the motion of a vane under given operating conditions. In addition, a method of measuring the pressure affecting the movement of the vanes is discussed.
2016-04-05
Technical Paper
2016-01-1381
Jiaqi Li, Jimin Ni, Xiuyong Shi
Abstract Sealing system is an important subsystem of modern high-performance engine. Sealing system reliability directly affects the engine operating conditions. Cylinder head gaskets(CHG) sealing system is of the most importance to the engine sealing system, which is not only responsible for sealing chamber, the cooling fluid and lubricating oil passage, for preventing gas leakage, water leakage and oil leakage, but also responsible for force transferring between cylinder head and cylinder body. Basing on nonlinear solution method, the sealing performance of multi-layer-steel cylinder head gaskets to a gasoline engine is studied with the finite element software ABAQUS. The deformations of the cylinder liners and engine block are also considered.
2016-04-05
Technical Paper
2016-01-1388
Baoke Huang, Jun Sun, Hu Wang, Xiaoyong Zhao, Qin Teng
Abstract In current design optimization of engine crankshaft bearing, only the crankshaft bearing is considered as the studying object. However, the corresponding relations of major structure dimensions exist between the crankshaft and the crankshaft bearing in engine, and there are the interaction effects between the crankshaft and the crankshaft bearing during the operation of engine. In this paper, the crankshaft-bearing system of a four-cylinder engine is considered as the studying object, the multi-objective design optimization of crankshaft bearing is developed. The crankshaft mass and the total frictional power loss of crankshaft bearings are selected as the objective functions in the design optimization of crankshaft bearing. The Particle Swarm Optimization algorithm is used in the optimization calculation. The optimization results are compared to the ones of original engine design and the single-objective design optimization of crankshaft bearing.
Viewing 91 to 120 of 6706

Filter

Subtopics