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Viewing 1 to 30 of 2839
2016-10-17
Technical Paper
2016-01-2353
Kazunori Harima, Shinji Tsuchiya, Takuro morino, Yuji Nagasawa
CVT belts are constructed with multiple elements and layered rings, and friction loss occurs between each parts. Due to belt geometry, a large belt friction loss occurs between the elements and the inner most ring. Therefore, to improve efficiency, it is effective to decrease the slip between the elements and the inner most ring. So, the torque transmitted is influenced by the slip between the elements and the inner most ring. When the slip is decreased, it is thought that the amount of torque transmitted by the ring change. For efficiency improvement, it is necessary to analyze the change of the torque transmitted by the ring due to the decrease of slip between the elements and the inner most ring, but to verify of the internal thrust force in the real load state is difficult because it is a phenomenon inside the belt.
2016-10-17
Technical Paper
2016-01-2354
Aaron J. Conde, Louis-Philippe Gagne, Martha Christenson, Brad Richard, Ian Whittal
Six vehicles were tested on a chassis dynamometer in order to characterize the differences in vehicle performance between vehicles equipped with various AWD powertrains and their 2WD counterparts. Three pairs of vehicle models from three separate vehicle manufacturers were chosen. The first two vehicle models are AWD vehicles that are equipped with a differential split that can deliver power the rear axle, when needed. The third vehicle employs an axle disconnect system which completely disconnects the rear axle, allowing the vehicles to operate in 2WD. 2WD vehicles were tested on a single-axle dynamometer and the AWD vehicles were tested on a double-axle dynamometer. Each vehicle was tested on four different drive cycles (FTP-75, HWFCT, US06, Cold FTP) as well as the SC03 drive cycle, when available. Vehicle emissions were measured for all cycles including CO, CO2, NOX, THC, and TPM.
2016-10-17
Technical Paper
2016-01-2357
Onkar P. Gurav, Santosh Deshmane
Globalization has intensively driven focus of car manufacturers on comfort and ergonomics. Luxuries are becoming essential features of product mix. Customer’s expectations and desires are changing because of cut throat competition and increasing variety of options. In order to sustain in marketplace OEM has to be competitive while providing features and options with appropriate quality. Vigorously changing dimensions and definitions of comfort level, luxury and aesthetics driven the intense focus of OEM’s on customer touch points, customer touch points are those components of vehicle which customer accesses while driving the vehicle and they play vital role in generating drive feel of vehicle. Customers drive feel about the vehicle is most complex and critical factor and is of subjective nature. Now days drive feel is an important aspect of product differentiation. Gear shift feel is very crucial touch point in overall drive feel of vehicle.
2016-10-17
Technical Paper
2016-01-2356
Geng Li
A set of test bench of manual transmission efficiency is designed,which is used to research the transmission efficiency of manual transmission in different working conditions. This paper introduces the basic structure and control principle of the test bench and analyzes the impact of the gearbox lubricating oil temperature and load on the transmission efficiency according to the measured data. The bench adopts two AC asynchronous motor to simulate the driving and load of the vehicle,the upper computer of test bench uses C++ to write the control program,the lower computer adopts PLC to control S120 Control cabinet which is used to adjust the speed of driving motor and the torque of load motor,the upper computer and the lower computer communicate through the OPC protocol.The bench collects experimental data signal and outputs the corresponding control signal by NI PCI-6221 data acquisition card.
2016-09-27
Technical Paper
2016-01-8067
Suresh Kumar Kandreegula, Kamal Rohilla, Gaurav Paliwal, Naveen Sukumar, Naveen Pratap Tripathi
Three on the tree. Four on the Floor. The gear change mechanism is a component that is too often taken for granted but it is one of the more important features of the vehicle. It must be quick and smooth in action, efficient and totally reliable. Modern driving conditions demand that the driver makes frequent gear changes and a mechanism that is temperamental or inaccurate can be both frustrating and dangerous as well as physically tiring. The gear changing mechanism starts, quite obviously, with the gear lever. Most stem from the fact that a gear lever must move in two planes, forward and back and then from side to side to move across the gear "gate". A good many drivers think of gear changing as one simple action. This is more a tribute to the design of gear changing mechanisms than a reality.
2016-09-27
Technical Paper
2016-01-8069
MahendraMohan Rajagopal, Suresh Kumar N, Nageshwara Rao P
Current tractor drivelines were geared up to accommodate new technologies and updates experienced throughout the industry. One such phenomenon is the use of wet clutch in forward and reverse application. These applications include agriculture, livestock, construction, material handling, etc. In all such applications, gears that are connected with the wet clutch assembly experiences severe tooth misalignments. All these misalignments in such heavy duty application propagates drastically while handling severe loads and tends to shift the load distribution in a gear pair to an un-biased manner along the facewidth, which in turn increases the contact and bending stresses. These misalignments can also add few more decibels to the driveline system which will be an annoyance to the user.
2016-06-17
Journal Article
2016-01-9141
Vinod Saini, Sanchit Singh, Shivaram NV, Himanshu Jain
Abstract In this paper, an optimization method is proposed to improve the efficiency of a transmission equipped electric vehicle (EV) by optimizing gear shift strategy. The idea behind using a transmission for EV is to downsize the motor size and decrease overall energy consumption. The efficiency of an electric motor varies with its operating region (speed/torque) and this plays a crucial role in deciding overall energy consumption of EVs. A lot of work has been done to optimize gear shift strategy of internal combustion engines (ICE) based automatic transmission (AT), and automatic-manual transmissions (AMT), but for EVs this is still a new area. In case of EVs, we have an advantage of regeneration which makes it different from the ICE based vehicles. In order to maximize the efficiency, a heuristic search based algorithm - Genetic Algorithm (GA) is used.
2016-06-15
Journal Article
2016-01-1852
Ehsan Fatourehchi, Vishak Elisaus, Mahdi Mohammadpour, Stephanos Theodossiades, Homer Rahnejat
Abstract Efficiency and durability are key areas of research and development in modern racing drivetrains. Stringent regulations necessitate the need for components capable of operating under highly loaded conditions whilst being efficient and reliable. Downsizing, increasing the power-to-weight ratio and modification of gear teeth geometry to reduce friction are some of the actions undertaken to achieve these objectives. These approaches can however result in reduced structural integrity and component durability. Achieving a balance between system reliability and optimal efficiency requires detailed integrated multidisciplinary analyses, with the consideration of system dynamics, contact mechanics/tribology and stress analysis/structural integrity. This paper presents an analytical model to predict quasi-static contact power losses in lubricated spur gear sets operating under the Elastohydrodynamic regime of lubrication.
2016-05-01
Journal Article
2015-01-9144
Marc-Olivier Lacerte, Gabriel Pouliot, Jean-Sébastien Plante, Philippe Micheau
Electric Vehicles (EVs) with single-ratio gearbox provide high levels of smoothness, but using multi-speed gearbox can provide significant benefits in terms of vehicle acceleration, top speed, powertrain cost, mass, and energy consumption. In particular, Automated Manual Transmissions (AMTs) have characteristics of smooth shifts without torque interruption when coupled to a torque bypass clutch. However, conventional friction clutches are not best suited as torque bypass clutches because of their limited controllability and because large amount of heat must be dissipated to slow down the motor during gearshifts. This paper studies the feasibility of a seamless AMT architecture for EVs and Hybrid Electric Vehicles (HEVs) using an eddy current torque bypass clutch that is highly controllable, robust, low cost, and has no wearable parts.
2016-04-11
Journal Article
2016-01-9016
Mohammad Gerami Tehrani, Juuso Kelkka, Jussi Sopanen, Aki Mikkola, Kimmo Kerkkänen
Abstract The feasibility of improving the energy efficiency of Electric Vehicles (EV) by manipulating operation points by means of a variable transmission is investigated with an efficient mathematical model of power losses in all driveline components. Introduced model can be solved in real-time making it possible to embed it to a control scheme of EV. Empirical test results are employed to derive the efficiency of the power electronics and electric motor at operation points while the mechanical power losses are predicted by a comprehensive and generic formulation for efficiency analysis. The simulation model used comprises electrical component efficiency, drivetrain inertias, gearbox efficiency, regenerative braking, and gear ratio selection. Three different transmission types are studied in this work; a single reduction gear, a five-step gearbox and an Infinitely Variable Transmission.
2016-04-05
Technical Paper
2016-01-1007
Benjamin Ellies, Charles Schenk, Paul Dekraker
Abstract As part of its technology assessment for the upcoming midterm evaluation (MTE) of the 2022-2025 Light-Duty Vehicle Greenhouse Gas (LD GHG) emissions standards, EPA has been benchmarking engines and transmissions to generate inputs for use in its Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) model, a physics-based, forward-looking, full vehicle computer simulation tool. One of the most efficient engines today, a 2.0L Mazda SkyActiv engine, is of particular interest due to its high geometric compression ratio and use of an Atkinson cycle. EPA benchmarked the 2.0L SkyActiv at its National Vehicle and Fuel Emissions laboratory. EPA then incorporated ALPHA into an engine dynamometer control system so that vehicle chassis testing could be simulated with a hardware-in-the-loop (HIL) approach.
2016-04-05
Technical Paper
2016-01-1061
Guiping Yue, Wenbo Niu, Jian Zhao, Dandan Kong, Yun Li, Hangsheng Hou
Abstract Gear whine noise impacts customer perception of vehicle interior quietness in general and sound quality in particular. It has been a frequently occurred annoying phenomenon during vehicle development and much discussed topic regarding transmission NVH refinement in automotive industry. This work pertains to a transmission gear whine issue encountered in prototype evaluations during a vehicle program development process. The effort centers itself on the optimization of transmission gear macroscopic and microscopic parameters to fix the issue which is deemed unacceptable for customers. Specifically, by using multi-body dynamics approach, this work carries out a transmission system whine noise simulation based on optimal gear macro parameter selection and micro tooth flank modification. The obtained results show that the proposed design changes could successfully resolve the issue, which is verified by subsequent test measurement and confirmed by subjective evaluations.
2016-04-05
Technical Paper
2016-01-1177
Aditya Dhand, Keith Pullen
Abstract There are different types of energy storage devices which are used in today’s hybrid and electric vehicles. Batteries, ultra capacitors and high speed flywheels are the most commonly used ones. While batteries and supercapacitors store energy in the form of electric energy, the flywheel (FW) is the only device that keeps the energy stored in the original form of mechanical energy the same as the moving vehicle. The flywheel needs to be coupled to the driveshaft of the vehicle in a manner which allows it to vary its speed independently of the moving vehicle in order to vary its energy content. In other words a continuously variable transmission (CVT) is needed. The common mechanical variators used in automotive applications, namely the rolling traction drives and the belt drives, have the disadvantage that their speed ratio range defined as the maximum to minimum speed ratio is generally not sufficient for flywheel energy storage system (FESS).
2016-04-05
Technical Paper
2016-01-1358
Jerry Lai, Youssef Ziada, Juhchin Yang
Abstract During the planetary gear assembly, staking is a widely-used method for affixing pinion shafts onto the position. A reliable staking process not only prevents the movement of shaft during transmission operation, but also minimizes the distortion of the assembly due to the staking process. The quality of staking operations is determined by the component designs, the process parameters, and the staking tool geometry. It would be extremely time-consuming and tedious to evaluate these factors empirically; not even mention the requirement of prototypes in the early stage of a new program. A Finite Element methodology is developed to simulate the complete staking process including shaft press in, staking, and after staking tool release. The critical process parameters, such as staking force, staking length, shaft and holes interference amount, etc., are then evaluated systematically.
2016-04-05
Technical Paper
2016-01-1378
Takanori Ide, Kentaro Toda, Yasunori Futamura, Tetsuya Sakurai
Abstract Efficient method to solve large-scale eigenvalue problem in vibration is presented. NVH (Noise, Vibration and Harshness) performance is an important quality measure of vehicles. Therefore, the reduction of vibration is one of the key considerations of new automatic transmission design. In addition, reduction of product design time is another important requirement. Computer Aided Engineering (CAE) is becoming a more important methodology to reduce product design time. However, computational time of eigenvalue problem takes long. We propose parallel eigenvalue computation (Sakurai-Sugiura method) for large-scale eigenvalue problems. This method has a good parallel scalability according to a hierarchical structure of the method. As the demonstrative problem, we consider large-scale computation of eigenvalue problem for AISIN AW FWD automatic transmission.
2016-04-05
Technical Paper
2016-01-1386
Miho Kumagai, Masaki Otomori, Takanori Ide, Takayuki Yamada, Kazuhiro Izui, Shinji Nishiwaki
Abstract This paper presents a study on a design methodology for lightweight automatic transmission parts for vehicles. To improve fuel economy of the vehicle, weight reduction is a primary issue when designing automobile parts. Topology optimization, a particularly flexible type of structural optimization method, is an effective tool for developing lightweight designs. However, topology optimization methods available in most commercial software often provide optimization results that include grayscale areas, which cause the designs to be impractical from an engineering and manufacturing standpoint. To overcome this difficulty, we apply a level set-based topology optimization method that yields clear optimal configurations and therefore facilitates further improvement of the product design by engineers. In addition, we consider the imposition of a uniform cross-section constraint to improve the manufacturability of the obtained optimization results.
2016-04-05
Technical Paper
2016-01-0003
Alberto Taraborrelli, Francesco Braghin
Abstract This paper reports the studies, design and developments of an electronic electro-actuated gearshifter installed on the DP7, which is Politecnico di Milano car that took part at Formula SAE 2015 competitions in Hockenheim and Varano dè Melegari. The original idea was born to replace the hydraulic gearshift system used until 2011 because of its high weight and cost. After many evaluations about the kind of technology to use, made by previous team members in the electronic department, the final project was a fully electric shifter. This system has proven its qualities among which are lightness and low cost.
2016-04-05
Technical Paper
2016-01-0089
Mohamed Samy Barakat, Mohamed Abdelaziz
Abstract This Application is using Multilayer Perceptron Algorithm to predict the shifting gear timing based on throttle percentage, vehicle velocity, time history and engine speed, in order to enhance the fuel efficiency, shifting time, power loss and driver’s comfort during shifting. The model makes no assumptions about how transmission performance aspects like gears slipping time or the existence of distinct environments like high temperature affects the power train system performance. Instead, the model can learn to model any type of distortion or additive noise in the sensor data; induced in the CAN protocol, through sufficient training data characterization. The network will be implemented on an AMESim model to characterize the operating temperatures and optimize the gearbox design to work with an optimal temperature and advance to this temperature during operation.
2016-04-05
Technical Paper
2016-01-0623
Gopal Athani, Kapil Dongare, Srinivasa Gavarraju
Abstract Micro and Mild Hybrid Systems is a bracket term, which covers functions like Engine Stop/Start (ESS), Intelligent Alternator Control (IAC), and many others, which collectively aim at optimizing the fuel consumption by preventing the wasteful running of the engine. Engine Stop/Start system is the prominent part of the Micro/Mild hybrid systems and is the most significant contributor while reducing the fuel consumption and greenhouse gas emissions. In the previous work of the Authors, various issues related to ESS were discussed in detail. ESS is not so popular among the customers, due to the complexities of the system operation and poor integration of the system design with the customer behavior. In addition, due to various functional safety conditions, and the traffic conditions, the actual benefits of ESS are negatively impacted. Therefore, it becomes necessary to have a different approach to the design of the systems like ESS.
2016-04-05
Technical Paper
2016-01-0422
Robert A. Smith, Christopher Rudzinskas
Abstract Samples of 33% glass filled and unfilled poly(butylene terephthalate) [PBT] and nylon 66 (PA66) were injection molded into bars,which were immersed in common engine and powertrain fluids: antifreeze, motor oil and automatic transmission fluid for 25 days. Fluid uptake was measured at 1, 7, 18, and 25 days by gravimetry. Both PBT samples absorbed 0.2-0.25% antifreeze and 0.05 - 0.10% motor oil and automatic transmission fluid (ATF). Both DSC and DMA analysis showed no disruption of polymer thermal transitions or storage moduli. The glass filled PA66 sample absorbed 2.5% antifreeze and 0.25-0.3% of motor oil and ATF and showed an 80°C reduction in the tan delta maximum on DMA. The unfilled PA66 sample absorbed 7% antifreeze and 0.2-0.3% of motor oil and ATF also showed a tan delta maximum 80°C less than the unexposed control. Creep analysis was conducted on the unfilled nylon sample and compared to a virgin material.
2016-04-05
Technical Paper
2016-01-0431
Guangqiang Wu, Huwei Wu, Xiang Chen
Abstract The nonlinear characteristics impact of multi-staged stiffness clutch damper on the vehicle creeping is investigated by using the lumped-parameter modeling method as a certain mass-production passenger sedan is taken as the research subject. Firstly, a quasi-transient engine model of an inline four-cylinder and four-stroke engine, based on measured data of cylinder gas pressure versus crankshaft angle, is derived. Effective output torque is acquired and as the input excitation to the driveline system. Secondly, a 12-DOF (Degree of Freedom) nonlinear and branched powertrain system and vehicle longitudinal dynamics model is established. The differential mechanism characteristics and dynamic tire property based on the LuGre tire model are considered. Then, for a traditional two-staged stiffness clutch damper in consideration of hysteresis characteristics, vehicle powertrain system responses in both the time and frequency domain are obtained.
2016-04-05
Technical Paper
2016-01-1294
Jonggyu Kim, Pyoung Beom Kim, YoungChan Lee, Sunghee Jung, Byeong-Ug Choi
Abstract This study presents the NVH characteristics of a passenger vehicle with a three-cylinder engine and a Continuously Variable Transmission (CVT) and an optimization procedure to achieve balance between fuel economy and NVH. The goal of this study is to improve fuel economy by extending the lock-up area of the damper clutch at low vehicle speed and to minimize booming noise and body vibration caused by the direct connection of the engine and transmission. Resonance characteristics of the chassis systems and driveline have been studied and optimized by the experiment. NVH behavior of the vehicle body structure is investigated and modifications for refinement of booming and body vibration are proposed by simulation using MSC NASTRAN. Calibration parameters for CVT control are optimized for fuel economy and NVH.
2016-04-05
Technical Paper
2016-01-0682
Jason King, Luke Barker, James Turner, John Martin
Abstract SuperGen is a Belt Integrated Starter Generator (B-ISG) combined with a novel electro-mechanical power split transmission system providing variable speed centrifugal supercharger capability, all in one compact package. This paper initially discusses the analysis of SuperGen application to a gasoline SUV in order to examine the BISG power and voltage mild hybrid functionality trade-off versus fuel consumption reduction on drive cycle. A significant engine down speeding was also applied based on the low speed torque enhancement afforded by SuperGen boosting capability, both transiently, and sustainably at steady state engine operation. This has been demonstrated and reported on the well-published Jaguar Land Rover (JLR) Ultraboost project.
2016-04-05
Technical Paper
2016-01-1172
Takashi Iwata, Kyosuke Mori, Taketoki Maruyama, Shinobu Nakamura, Yusuke Yoshida, Toshihiko Yamanaka
Abstract Recently, for the aspects of ecology and economy, fuel efficiency improvement demand has been increased globally. And, various types of hybrid systems have been suggested. In response to this market demand, AISIN SEIKI has been developing Synchronizer-less hybrid automated manual transmission (HV-AMT) system aiming excellent transmission efficiency, excellent agility, and shift change quality like a step automatic transmission (AT). This hybrid system is constructed based upon a parallel 2-axis manual transmission (MT) which originally has high transmission efficiency. The synchronizer system of a MT is replaced by a Dog clutch system which does not spoil the transmission efficiency and never makes failure in synchronization. This Dog clutch system includes a modified detent function, a shift actuator of linear motor, advanced function controls for a clutch and a shift actuator.
2016-04-05
Technical Paper
2016-01-1098
Jongsool Park
Abstract The market demands for CO2 reduction and fuel economy have led to a variety of new gear set concepts of automatic transmissions with 4 planetary gear sets and 6 shift elements in recent years. Understanding the relationship between the torque of clutch and brake and gear ratio in the design stage is very important to assess new gear set concepts and to set up the control strategy for enhancing shift quality and to reduce the heat generation of clutch and brake. In this paper, a new systematic approach is used to unify the relationship between torque and gear ratio during the gear shift for all multi-step planetary automatic transmissions. This study describes the unified concept model with a lumped inertia regardless of the specific transmission layout and derives the principal unified relationship equations using torque and energy analysis, which prove that the sum of brake torque is always gear ratio -1 in every in-gear.
2016-04-05
Technical Paper
2016-01-1100
Andrei Keller, Sergei Aliukov, Vladislav Anchukov, Stanislav Ushnurcev
Abstract The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity (it is defined as the distance traveled divided by the time elapsed), and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-toweight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical.
2016-04-05
Technical Paper
2016-01-1103
Andrei Keller, Sergei Viktorovich Alyukov
Abstract The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity (it is defined as the distance traveled divided by the time elapsed), and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical.
2016-04-05
Technical Paper
2016-01-1107
Jing Yuan
Abstract The belt clutching CVT drive has been developed for the scooter application. It utilizes the belt as a clutching mechanism instead of the traditional centrifugal clutch that is commonly employed in conjunction with the driven clutch of the drive train. By eliminating the centrifugal clutch, 48% mass reduction of the driven clutch has been achieved as well as cost saving. By placing the belt clutching directly at the engine crankshaft, fast throttle response and better vehicle acceleration/deceleration have been attained. The belt clutching mechanism demands a better performance belt to withstand the additional clutching induced wear and tear. The newly developed carbon cord belt, G Force™ C12, meets the challenge. The common edge cord pull-out failure mode is eliminated, and the overall wear is improved. An analytical program PTWork has been developed and proven to be instrumental in integrating CVT clutch hardware with the CVT belt.
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
2016-01-1094
Fang Liao, Weimin Gao, Yan Gu, Fei Kang, Yinan Li, Cheng Wang
Abstract Generally, the gear rattle noise prediction models are composed of the mass and stiffness elements. The proposals are about the gear inertia or backlash and the shaft inertia or stiffness, but there are many detailed designs in the same inertia, stiffness or backlash conditions. Therefore, these proposals can’t guide detailed designs. These models only investigate the rattle in the rotating degree, and ignore rattle contribution in the radical and axial directions. Those prediction models only consider one or several factors which affect the rattle noise performance. It is difficult to predict the influence of individual factor and multi-factors coupling on the gear rattle noise in a rattle simulation model.
Viewing 1 to 30 of 2839