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Viewing 1 to 30 of 5765
2017-10-03 ...
  • October 3-12, 2017 (4 Sessions) - Live Online
Training / Education Online Web Seminars
Continuously Variable Transmission (CVT) technology is both a theoretical and practical option that addresses a number of system level improvement opportunities within the automotive and mobility industries. Although this technology has been available for many years and is now fully matured as a production ready technology, it is often not fully understood. This web seminar presents a focused view of CVT technology in all its forms and implementations.
2017-09-26 ...
  • September 26, 2017 (1 Session) - Live Online
Training / Education Online Web Seminars
Hybrid powertrains have been on the market for more than a decade and have become one of the most successful alternative powertrains available today. More than a million hybrids are sold globally per year, primarily in Japan and the US. Some OEMs estimate that up to 80% of their light-duty vehicles may require some level of hybridization to meet upcoming CAFE regulations in the United States. Hybrids are also starting to make inroads into markets in Europe, and have recently been introduced to Chinese and Indian markets, among others. Basic information on hybrids is scattered among information sources, and is often difficult to synthesize.
2017-09-25 ...
  • September 25-26, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
An efficient, robust, and quiet running drivetrain is as essential to customer satisfaction as styling and interior creature comforts. In this seminar, you will be exposed to various methods that can be used to accomplish this goal. Designed to help you visualize both individual components and the entire drivetrain system - without reference to complicated equations - this seminar focuses on the terms, functions, nomenclature, operating characteristics and effect on vehicle performance for each of the drivetrain components.
2017-08-07 ...
  • August 7-9, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • December 4-6, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Starting with a look at the transmission's primary function -- to couple the engine to the driveline and provide torque ratios between the two -- this updated and expanded seminar covers the latest transmission systems designed to achieve the most efficient engine operation. Current designs, the components and sub-systems used, their functional modes, how they operate, and the inter-relationships will be discussed. A manual transmission display will be used to explain ratios and how they function within the driveline.
2017-06-05
Technical Paper
2017-01-1769
Onkar Gangvekar, Santosh Deshmane
In today's automobile market, most of OEM's uses manual transmission for Cars. Gear Shifting is a crucial customer touch point. Any issue or inconvenience caused while shifting gear can result into customer dissatisfaction and will affect the brand image. Synchronizer is a vital subsystem for precise gear shifting mechanism. Based on vehicle application selection of synchronizer for given inertia and speed difference is the key factor which decides overall shift quality of gearbox. For more demanding driver abuse conditions like skip shifting, conventional brass synchronizers have proved inadequate for required speed difference and gear inertia and which eventually results into synchronizer crashing and affects driving performance. To increase synchronizer performance of multi-cone compact brass synchronizer, a grit blasting process has been added. These components are tested with Accelerated test plan successfully.
2017-06-05
Technical Paper
2017-01-1820
Martin Sopouch, Josip Hozmec, Alessandro Cadario
This paper presents a simulation environment and methodology for noise and vibration analyses of a driven rear axle in a bus application, with particular focus on medium to high frequency range (400 Hz to 3 kHz). The workflow demonstrates structure borne noise and sound radiation analyses. The fully flexible Multi–Body Dynamics (MBD) model - serving to cover the actual mechanical excitation mechanisms and the structural domain – includes geometrical contacts of hypoid gear in the central gear and planetary gear integrated at hubs, considering non-linear meshing stiffness. Contribution of aforementioned gear stages, as well as the propeller shaft universal joint at the pinion axle, on overall axle noise levels is investigated by means of sensitivity analysis. Based on the surface velocities computed at the vibrating axle-housing structure the Wave Based Technique (WBT) is employed to solve the airborne noise problem and predict the radiated sound.
2017-06-05
Technical Paper
2017-01-1800
Robert White
Several analytical tools exist for estimating a driveshaft’s critical speed, from simple elementary beam theory to sophisticated FEA models. Ultimately, nothing is better than a test, because no one will argue with the outcome from a well-designed measurement. Impact response measurements are easy, but they tend to over predict the critical speed. A test which sweeps the shaft speed up until failure is telling, but the speed causing failure is strongly dependent on even small amounts of variation in rotor unbalance. Waterfall plots of shaft displacement measurements offer the best indication of critical speed, however sometimes the resonance isn’t clearly seen or multiple resonances exist, making the critical speed unclear. A method less susceptible to system variation is offered here, fitting shaft orbit measurements to the theoretical single degree of freedom equation.
2017-06-05
Technical Paper
2017-01-1780
Yong Xu
Research Objective: For MT vehicles, gearbox rattle is a common NVH problem which influences the comfort level of vehicle. In order to prevent rattle in the design phase of vehicle, this work aimed to study the excitation mechanism and influence factors of gearbox rattle, and then to propose effective measures. Methodology: First, the root cause of gearbox rattle problem was studied with the aid of classical dynamical theories. And then the simulation model of vehicle powertrain system was built via Matlab-Simulink. Then some critical parameters of the model and some experiential optimum proposals were selected to perform a sensitivity analysis on the torsional vibration, which is the root cause of rattle. Referring the simulation results, the dual-mass flywheel was selected as the most effective solution to gearbox rattle. Results: The simulation results indicated the critical parameters for optimization to prevent gearbox rattle problem in the design phase of the vehicle.
2017-06-05
Technical Paper
2017-01-1768
Yong Xu
Purpose: For rear-wheel-drive (or all-wheel-drive) vehicles, the vibration and noise that caused by driveshaft often become the main factors that influence the comfort level of vehicle. In order to control and improve the NVH problems related to driveshaft, this work aimed to study the excitation mechanism and transfer path of driveshaft vibration, and then to propose effective measures. The purpose of this work was to propose an effective way to improve the NVH performance by controlling the additional excitation force of U-joints in the early phase of project. Methodology: First, the rotation order characteristics of driveshaft were studied with the aid of classical dynamics. Then a rigid-elastic coupling model of vehicle powertrain was modelled with the theory of multi-body dynamics. By inputting the actual vehicle parameters into the model, the acceleration operation of vehicle could be simulated.
2017-06-05
Technical Paper
2017-01-1778
Enrico Galvagno, Antonio Tota, Mauro Velardocchia, Alessandro Vigliani
This paper explores the potentiality of reducing noise and vibration of a vehicle transmission thanks to powertrain control integration with active braking system. The torsional backlashes between transmission rotating components (gears, synchronizers, splines, CV joints), in the presence of external disturbances, coming from the driver, e.g. during tip-in / tip-out maneuvers, or from the road, e.g. crossing a speed bump or driving on a rough road, may lead to NVH issues known as clonk. In this study, first of all the positive effect of a brake torque application at the driving wheels during such maneuvers on transmission NVH performance is shown. After that, a powertrain/brake integrated control strategy is proposed. The braking system is activated in advance with respect to the perturbation and it is deactivated immediately after to minimize the energy loss.
2017-06-05
Technical Paper
2017-01-1823
Dennis J. Kinchen
Powertrain mounting systems design and development involves creating and optimizing a solution using specific mount rates and multiple operating conditions. These mount rates become the recommended “nominal” rates in the specifications. As is typical of natural materials, the properties have variation resulting in a tolerance around the nominal specification which leads to differences in noise and vibration performance. A system that is robust to this variation is desired. The design and development process requires evaluation of these mounts to ensure that the noise and vibration performance is consistently met. During the hardware development of the powertrain mounting system a library of mounts that include the range of production variation is studied however this is time consuming. In this paper, a methodology is described to reduce the hardware evaluation time and provide a recommended optimal solution that is robust in the presence of production mount property variation.
2017-06-05
Technical Paper
2017-01-1829
Guillaume Loussert
The new fuel efficiency and emission standards have forced OEMs to put emphasis on different strategies such as engine downsizing, cylinder deactivation... Unfortunately these new technologies may lead to increased powertrain vibrations generated by the engine and transmitted to the chassis and the car cabin, such that their reduction or elimination has become a key topic for the automotive industry. The use of active engine mounts, acting directly on the fluid of an hydromount, or active vibration dampers, acting as an inertial mass-spring system, are very effective solutions, particularly when using electromagnetic based actuators. Nevertheless, all electromagnetic actuators technologies are not equals and the choice of such actuators must be considered carefully by taking into account the full performances and the overall cost of the solutions. This paper presents an electromagnetic actuator technology, that can be considered as the best tradeoff between performances and cost.
2017-06-05
Technical Paper
2017-01-1845
Jon Furlich, Jason Blough, Darrell Robinette
When subjected to high speeds and high torques, a vehicle driveshaft and other powertrain components experience an increase in stored potential energy. When the engine and driveshaft are decoupled during an up or down shift, the potential energy is released causing clutch clatter during the shift event. A smooth shift is desired by the customer thus reduction of the clutch clatter will improve customer experience and satisfaction. In this study, a six speed MT, RWD passenger car was used to experimentally capture acoustic and vibration data during the clutch clatter event. To successfully replicate the in-situ results additional data was collected and analyzed for powertrain component roll, and pitch from the test vehicle. These boundary conditions were applied to a reduced car model in a lab environment to successfully replicate the clutch clatter event on a stationary test stand.
2017-06-05
Technical Paper
2017-01-1779
Xianwu Yang, Jian Pang, Lanjun Wang, Xiong Tian, Yu Tang
With the development of automobile industry, the higher NVH performance is required for customers, and with drastically reduction of engine noise, the gear rattle noise generated by the impact between neutral gears inside transmission can be much easily perceived. It is well known that the torsional mode of powertrain system has a direct relationship with transmission gear rattle noise, the higher torsional vibration leads to more serious gear rattle noise. This paper establishes a torsional model of a front wheel drive automotive drivetrain, including clutch system, transmission box and equivalent load of a full vehicle in AMESim software. The experimental engine speed fluctuations at different gears are used to excite the torsional model.
2017-06-05
Technical Paper
2017-01-1907
Yang Wang, Yong Xu, Xiao Tan
OPTIMIZATION OF THE POWERTRAIN MOUNTING SYSTEM VIA DOE METHOD Authors: Wang Yang*, Wang Hui*, Xu Yong* * NVH Section, Brilliance-Auto Engineering Research Institute, Shenyang, China, 110141 Key Words: NVH; DOE; Powertrain Mounting System; Analysis of Variance Research and/or Engineering Questions/Objective The vibration isolation performance of vehicle powertrain mounting system is mostly determined by the three-directional stiffnesses of each mount block. Because of the manufacturing tolerance and the coupling effect, the stiffnesses of mounts cannot be maintained stable. The purpose of this study was to find out the way to optimize the stiffnesses of mounts via the design of experiments (DOE). Methodology According to the DOE process, a full factorial design was implemented. The z-direction stiffnesses of three mount blocks in the mounting system were selected as the three analysis factors.
2017-06-05
Technical Paper
2017-01-1835
Nader Dolatabadi, Ramin Rahmani, Stephanos Theodossiades, Homer Rahnejat, Guy Blundell, Guillaume Bernard
Clutches are commonly utilised in passenger type and off-road heavy-duty vehicles to disconnect the engine from the driveline and other parasitic loads. In off-road heavy-duty vehicles, fuel efficiency and start-up functionality at extended ambient conditions, such as cold start-up and low intake absolute pressure are crucial. Off-road vehicle manufacturers usually overcome the parasitic loads in these conditions by oversizing the engine. Caterpillar Inc. as the pioneer in the off-road technology has developed a novel clutch design to allow for engine downsizing while vehicle’s performance is not affected. The tribology behaviour of clutch will be crucial to start engagement in time and reach the maximum clutch capacity in the shortest possible time and the safest method in terms of dynamics. A multi-body dynamics model of the clutch system is developed in MSC ADAMS. Flywheel carries the same speed and torque as engine and represents the engine input to the clutch.
2017-06-05
Technical Paper
2017-01-1818
Ramya Teja, T. R. Milind, Rodney C. Glover, Sunil Sonawane
Helical gears are used more commonly than spur gears due to their higher load carrying capacity, efficiency and lower noise. Helical gear pairs consist of base and axial planes in the plane of action. Transmission Error (TE) is considered as a dominant source of gear whine noise so gears pairs are analyzed and designed for lower TE. In process of designing helical gears for lower TE, the shuttling moment can be a significant excitation source. A shuttling moment is caused by the shifting of the centroid of the tooth normal force back and forth across the lead. Shuttling force is produced by a combination of design parameters, misalignment and manufacturing errors. Limited details are available on this excitation and its effect on overall noise radiated from the gear box or transmission at is gear mesh frequency and harmonics. LDP provides shuttling force as a bearing force in the base plane direction at one edge of the face width only.
2017-06-05
Journal Article
2017-01-1777
Thomas Wellmann, Kiran Govindswamy, Dean Tomazic
The automotive industry continues to develop new technologies aimed at reducing overall vehi-cle level fuel consumption. Powertrain and driveline related technologies will play a key role in helping OEM’s meet fleet CO2 reduction targets for 2025 and beyond. Specifically, use of tech-nologies such as downsized engines, idle start-stop systems, aggressive torque converter lock-up schedules, wide-ratio spread transmissions, and electrified propulsion systems are vital to-wards meeting aggressive fuel economy targets. Judicious combinations of such powertrain and driveline technology packages in conjunction with measures such as the use of low rolling resistance tires and vehicle lightweighting will be required to meet future OEM fleet CO2 targets. Many of the technologies needed for meeting the fuel economy and CO2 targets come with unique NVH challenges. In order to ensure customer acceptance of new vehicles, it is impera-tive that these NVH challenges be understood and solved.
2017-06-05
Journal Article
2017-01-1772
Yawen Wang, Xuan Li, Guan Qiao, Teik Lim
The prediction and control of gear vibration and noise has become very important in the design of a quiet, high-quality gearbox systems. The vibratory energy of the gear pair caused by transmission error excitation is transmitted structurally through shaft-bearing-housing assembly and radiates off from exterior housing surface. Most of the previous studies ignore the contribution of components flexibility to the transmission error. In this study, a system level model of axle system with hypoid gear pair is developed, aiming at investigating the effect of the elasticity of the shafts, bearings and housing. The load distribution results and gear transmission errors are calculated and compared between different assumptions on the boundary conditions. A series of parametric studies are also performed to analyze the effects of various shaft-bearing configurations and properties on the dynamic responses of the geared system.
Viewing 1 to 30 of 5765

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