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Viewing 1 to 30 of 612
2004-10-26
Technical Paper
2004-01-2677
David Milligan, Ulf Engström, Ryu Goto
Powder Metallurgy (P/M) is an increasingly viable alternative for applications requiring high material performance. Continuous advances in alloy systems and processing techniques, combined with powder metallurgy's ability to produce complex net shapes, have made it possible for powder metallurgy to compete with other technologies in engine and transmission applications. This paper will focus on new alloy systems and advanced processing techniques. The properties achievable with currently available materials, such as chromium containing materials, combined with advanced processing techniques, such as warm compaction and surface densification, will be presented. Additionally, a case study where a warm compacted synchronizing latch cone in a heavy duty truck transmission was found to have equal or superior performance to precision forged and powder forged latch cones.
2004-10-26
Technical Paper
2004-01-2722
Klaus Steinel, Gerhard Tebbe
Comfort requirements have significantly increased in recent years, even in the commercial vehicle sector. Transmission noise, caused by higher engine excitation (due to emission changes), can be reduced with a new torsional damper in the clutch disc, with a special idle damper. Up until now, free play (sometimes referred to as backlash) in the clutch or transmission helped reduce idle rattle. In many cases this simple solution is no longer adequate. This paper explains dynamic behavior during idling and provides the background for understanding the causes of rattle noise.
2013-01-09
Technical Paper
2013-26-0133
Arvind R, Jayagopal S, Suryanarayanan V, Porpatham E, Senthil Kumar A
Brazil has implemented a new emission regulation for Light commercial vehicles named PROCONVE L6. This regulation follows Environmental Protection Act (EPA) driving cycle; FTP75. This cycle simulates an urban route of 12.07 km with frequent stops. The maximum speed is 91.2 km/h and the average speed is 31.5 km/h. The regulation has proposed that the gear shift pattern of the manual transmission vehicle can be varied according to the manufacturer's specification. This has lead to the strategy of optimizing gear shift pattern without compromising diesel combustion and engine-out emission with optimized exhaust-gas treatment-devices. The emission is demonstrated to Brazilan Authorities with good margins.
2013-10-07
Technical Paper
2013-36-0264
Paola S Sant'Anna
Manual transmissions are used in a wide range of automotive applications such as commercial vehicles like trucks, buses and pick-ups as well on passenger car market. On manual transmissions is very common to use helical gears to transmit torque. Some of typical failure modes of these gears are tooth breakage, pitting and scoring. The objective of this paper is to present a case study of helical gear scoring issue on manual transmission and the design changes implemented in order to solve it. This material also shows the ultimate consequence of scoring problem on gear life and the co-relation of the part heat treatment case depth specification on this failure mode.
2014-04-01
Technical Paper
2014-01-0182
Raunak Santosh, Vijayakumar Chekuri
Abstract Rapid growth in the Indian economy has led to new market trends for commercial vehicles. Customers now expect high levels of comfort from all tactile points in a truck cabin; the gear lever knob is frequently used and its reactions greatly influence how a driver perceives Gear Shift Quality (GSQ) and thereby vehicle quality. The subjectivity of human perception is difficult to measure objectively; therefore this paper represents an objective methodology to correlate customer feedback of gearshift reactions. For the attribute evaluation of a set of intermediate commercial vehicles; detailed subjective appraisals were conducted by expert level assessors for GSQ sub-attributes, and a consecutive objective measurement was performed to investigate and substantiate these vehicle assessments.
2013-10-07
Technical Paper
2013-36-0336
Ana Cristina Soares, Lauro Catapano, Rogério Dias
Simulations tools like AVL Cruise and Vehicle Dynamics where used to carry on a comparative study between two trucks equipped with automated manual transmissions in two configurations: the original with 12 gears, and a proposal with 16 gears. The original configuration is world-wide used and in this way, the present study was fundamental to decide whether choosing the new proposal would bring the Brazilian option any advantages. In order to evaluate the whole vehicle behavior fuel consumption evaluation and vehicle performance were analyzed. From the present study, it was showed that the 16 gears transmission was the best alternative for the Brazilian application.
2011-04-12
Technical Paper
2011-01-0720
Lauren L. Thompson, Craig Jensen
Environmental concerns and government regulations are factors that have led to an increased focus on fuel economy in the automotive industry. This paper identifies a method used to improve the efficiency of a front-wheel-drive (FWD) automatic transmission. In order to create improvements in large complex systems, it is key to have a large scope, to include as much of the system as possible. The approach taken in this work was to use Design for Six Sigma (DFSS) methodology. This was done to optimize as many of the front-wheel-drive transmission components as possible to increase robustness and efficiency. A focus of robustness, or consistency in torque transformation, is as important as the value of efficiency itself, because of the huge range of usage conditions. Therefore, it was necessary to find a solution of the best transmission component settings that would not depend on specific usage conditions such as temperatures, system pressures, or gear ratio.
2011-09-13
Technical Paper
2011-01-2235
Rohit Kunal
This paper presents a simulation of the stiffness of the shift fork of a manual transmission using contact pattern analysis and optistrut. All the subsystem (i.e. synchronizer and the shift system component) are constrained to optimize the shift fork stiffness. A-5-speed manual transmission is used as an example to illustrate the simulation, co-relation and validation of the optimization of the gear shift fork stiffness. The shift system was modeled in the software to collate the synchronization force, shift system gap etc with the constraint on the shift fork. It is constrained by the synchronizer sleeve and the fork mounting on the gear shift rail. The synchronizer force is then applied on the gear shift fork pads which are translated to the synchronizer sleeve. It has a number of pads which come into contact at different occasion of the synchronization because of the varying stiffness of the fork.
1999-09-14
Technical Paper
1999-01-2811
Craig R. Eike, Guy T. Stoever
This paper will discuss the new Case MX Magnum® tractor transmission controls. They are electronically controlled, hydraulic valves that reduce transmission internal torque spikes, operator shift shock, complexity, and eliminated the need for periodic system calibration. The new system splits the controls into their simplest common denominators, and leverages commonality of parts and concepts to reduce both system and development costs. It maintains clutch pressure during low regulated pressure transients that occur during a shift, while compensating for clutch wear, to maintain the desired shift characteristics.
1999-11-15
Technical Paper
1999-01-3750
Marty Fletcher
The following information is intended to provide a front line perspective of what benefits have been realized in safety, driver acceptance, and customer service, given the level of technology available to the medium and heavy duty truck and bus industry today. It does not specifically address the manner or method of technology utilized for such achievement, moreover it addresses the enhancements that specific components have made possible. Personal experiences are presented to support the benefits and a wish list of the latest technology available concludes this presentation.
1999-11-15
Technical Paper
1999-01-3744
Richard J. Koenig, John D. Hylton
Light and Medium Duty Trucks (N.A. Classes 2–7) make up of a wide variety of vehicle configurations. These vehicles, in addition to providing the basic hauling needs of the industry, also provide distinct operational features dictated by the vocation they serve. This results in additional auxiliary equipment and control features being employed. The control system for Allison Transmission's new 1000/2000/2400 Series™ transmission was designed to satisfy the many requirements of this complex market. This paper will describe these features and how they interact with various control aspects of the vehicle. Also, future control features will be discussed.
1999-11-15
Technical Paper
1999-01-3743
Steven F. James, William J. Wegeng
Allison Transmission has developed a family of three new automatic transmission products, the 1000, 2000 and 2400 Series™, for the light and medium-duty commercial markets. This technical paper will discuss how Allison first identified the opportunity, established the market requirements, designed, and validated these new products.
2004-08-23
Technical Paper
2004-40-0054
A. William Brown, Jacques Van Rooij, Andrew A. Frank
The objective of this paper is to indicate the design principals of a Continuously Variable Transmission that is physically about the size of a conventional manual transmission for the same power and torque with an equal or better efficiency and durability. The CVT will be designed for use in either a hybrid electric drive or a conventional vehicle with the addition of a torque converter and reverse gear. The design objectives are as follows: 1. About the same size as a 5 or 6 speed manual transmission for North-South engine orientation and rear wheel drive. 2. About the same weight as the 5 or 6 speed manual transmission 3. Cost about the same or less 4. Much smaller than a comparable performance rated automatic transmission 5. Fewer parts than manual transmissions and less than 1/30th of the part count of an automatic. 6. Ratio span greater than equivalent manual or automatic transmissions. 7.
2012-09-24
Technical Paper
2012-01-1989
Jaideep Singh, Jagmindar Singh, Mangesh Dhane
Present day AMT unit uses two high pressure hydraulically operated pistons for select & shift operations which make the unit weigh around 8kg. Besides this it also makes the unit more complex & unreliable with a lot of torque interruption. The use of electrical servo motors steps in here as a better alternative as it provides a more precise and smoother shift. To test this we used a 5 Gear-Manual Transmission. For the selection, a precise 14.5 degree of twisting was required which was easily achieved by the servo motor. Further, shift of 10.5mm could be made possible by using the motor to shift the rack using a pinion on the shaft. This system then essentially eliminates the whole hydraulic circuit, the housing of actuator pack & power pack making it a simpler unit all together. A Motor is attached to the output shaft of the Transmission which drives in power while the AMT unit is making transition from one gear to another.
2012-09-24
Technical Paper
2012-01-2007
Shouwei Lu, Huihua Feng, Zhengxing Zuo
This paper provides an investigation to improve vehicle powertrain NVH performance via modification of excitation and radiation system of powertrain. First of all, considering different excitation mechanisms of the powertrain, the excitation forces are analyzed. The FEM/BEM coupled analysis and the acoustic transfer vector (ATV) calculation as well as panel contribution analysis are applied to investigating the acoustic characteristics of the powertrain. Then a hybrid approach which couples the transmission gear profile modification for attenuating gear system excitation and the transmission housing modification for reducing transmission housing noise radiation is proposed to improve powertrain NVH performance. Experiment validation is conducted in order to assess the modified results. The assessment shows that this hybrid approach can effectively predict and reduce powertrain noise and vibration.
2016-09-27
Technical Paper
2016-01-8019
Marius-Dorin Surcel, Adime Kofi Bonsi
Abstract The main objective of this project was to compare the fuel consumption and dynamic performances of direct-drive and overdrive transmission tractors. Fuel consumption was evaluated at constant high speed and on various road profiles, while the dynamic performance was assessed on various road profiles only. The SAE Fuel Consumption Test Procedure (J1526) was used for constant high speed fuel consumption track test evaluations. The direct-drive transmission tractor consumed less than the overdrive transmission tractor, even though it was heavier. The testing on various road profiles was conducted using a towing dynamometer, for comparing the dynamic capability of the tractors when simulating the same towing load on two hilly road profiles: the Townes Pass path (in the Rocky Mountains) and the Saguenay path (in the Saguenay region of Quebec). Each tractor was to haul the set load along the given path while trying to attain 90 km/h speed.
2016-09-27
Technical Paper
2016-01-8080
Yanwu Ge, Ying Huang
Abstract The ever-growing number of interacting electronic vehicle control systems requires new control algorithms to manage the increasing system complexity. As a result, torque-based control architecture has been popular for its easy extension as the torque demand variable is the only interface between the engine control algorithms and other vehicle control systems. Under the torque-based control architecture, the engine and AT coordinated control for upshift process is investigated. Based on the dynamics analysis, quantitative relationship between the turbine torque of HTC and output shaft torque of AT has been obtained. Then the coordinated control strategy has been developed to smooth the torque trajectory of AT output shaft. The designed control strategy is tested on a powertrain simulation model in MATLAB/Simulink and a test bench. Through simulation, the shift time range in which the engine coordinated control strategy is effective is acquired.
2017-01-10
Technical Paper
2017-26-0231
Bhagyesh Bhagwan Chavan, S Udayakumar
Abstract Synchronizer design optimization is being prime need for smooth gear shifting and shifting noise. Especially in tractors, synchronizers are subjected to different kinds of loads under various field applications such as Puddling, Cultivation, Haulage, Construction equipment, etc. Also, transmission housings act as a part of chassis of the tractor and hence subjected to sever bending loads. Thus, design & evaluation of tractor transmission, meeting the customer requirement is quite complex. Current trends in product development are driven by shortening development time, reduced cost and first-time-right principle. These above requirements drive tractor manufacturers to put more efforts on delivering quality, robust and reliable transmission assembly in time. Generally the synchronizer packs were validated at sub system level in test rig and further assembled on to the tractor to validate the same in tractor level it requires more time & high cost.
1923-01-01
Technical Paper
230017
S VON AMMON
A record of an investigation of heavy-duty truck-axles carried out by the Bureau of Standards at the request of the motor transport division of the Quartermaster Corps, this paper deals in particular with the mechanical efficiency of the axles tested. The investigation included, in addition to several worm-drive Class-B Army-truck axles with different types of bearing, a number of axles usually designated respectively as “internal-gear” and “multiple-reduction” type. Each of these types was represented by axles in successful use in commercial trucks of 5-ton rating. In analyzing the results of the tests it was found possible to separate the losses into no-load losses and load losses; the total loss being the sum of these two. In general, the no-load losses were primarily controlled by the viscosity and the method of application of the lubricant. They were greater in those axles in which the parts rotating at high speeds were immersed most completely in the lubricant.
2015-04-14
Technical Paper
2015-01-1104
Patrick Sexton, Robert A. Smithson, Gordon McIndoe
Abstract In order to introduce Dana's Variglide Continuously Variable Planetary (CVP) technology to the mobility industry, Dana has produced demonstrator transmissions for use in a rear wheel drive C-class car and in a fork lift truck. The intention is to illustrate how the CVP can be combined with conventional transmission technology to produce either a continuously variable transmission with the ratio range comparable to that of the latest step ratio transmissions, or used in a simple IVT configuration for off-highway applications. The co-axial design of the CVP allows it to package well into current drivetrain solutions. The ratio control of the device is fast, precise, and stable and the CVP does not require high power consumption for clamping. Multiple power flow configurations of the CVP are shown to blend well with current conventional transmission technology as well as future hybrid configurations.
2015-04-14
Technical Paper
2015-01-1127
Wenbin Liu, Gangfeng Tan, Xiaoqing Tian, Zhiqiang Hu, Yuanqi Gao, Zhi Li, Junyi Yuan, Wei Liu
Abstract The hydraulic retarder is an important auxiliary braking device for the heavy vehicle, which has some characteristics, such as the big brake torque and long duration braking, when the vehicle is traveling in braking state. However, the transmission power loss will be produced when the vehicle is traveling in non-braking state. This transmission power loss is called Air-friction. Firstly, the air flow distribution characteristics of retarder cavity are studied by computational fluid mechanics, and the Air-friction characteristic in different conditions is analyzed. Then, according to the Air-friction characteristics for the condition of different filling density, a set of vacuum air loss reduction system is designed. Meanwhile, the test bench for retarder Air-friction is set up, the test data of the revolution speed, pressure in cavity and air loss resistance is obtained according to the test bench for hydraulic retarder.
2015-09-29
Technical Paper
2015-01-2784
Aravindraj Alaguvel, Vijayakumar Chekuri
Abstract Improved economic growth and infrastructure in India has led to new market trends for commercial vehicles. Customers now expect high levels of comfort from all tactile points in a truck cabin; among them the gearlever knob is frequently used and its reactions greatly influence how a driver perceives gearshift quality (GSQ) and thereby vehicle quality. The importance of the gear shift quality of manual transmissions has increased significantly over the past few years as the refinement of other vehicle systems has increased. In Gearbox, synchroniser is the major component whose performance will affect the peak engagement force to a large extent. Synchroniser mechanism allows gear change to be smooth, noiseless and without vibrations. Since the maximum synchronisation effort vary depending on the rate of the shift actuation, it is difficult to compare synchronisers in different transmissions by force alone.
2015-09-29
Technical Paper
2015-01-2782
Sergei Viktorovich Aliukov, Andrei Keller, Alexander Alyukov
Abstract Free-wheel mechanisms transmit rotary motion in only one direction. They are widely used, for example, in hydraulic transformers, pulsed continuous transmissions, inertial automatic torque transformers, electrical starters for motors, and metal- and wood-working drives. Unfortunately, existing free-wheel mechanisms are insufficiently reliable and durable and in many cases limit the reliability of the drive as a whole. Thus, the insufficient life of free-wheel mechanisms delays the use of inertial automatic continuous transmissions, which have many benefits over existing transmissions. In most known free-wheel mechanism, the whole torque is transmitted through locking elements such as balls, rollers, eccentric wheels, pawls, slide blocks, and wedges, whose operation at large loads may limit the life of the mechanism.
2015-09-29
Technical Paper
2015-01-2789
Igor Taratorkin, Alexander Taratorkin, Viktor Derzhanskii
Abstract The article has represented the results of researching multiple wheeled chassis (MWC) hydromechanical transmission dynamic loading. On the basis of comparing frequencies of dynamic moment resonant fluctuations and frequencies of diesel engine indignation, the hypothesis about subharmonic resonance realization in the mechanical system having strong nonlinear elastic characteristic is offered and grounded. A method of tuning out undesirable fluctuations which form dynamic loading to take subharmonic resonant modes out of the engine rpm speed working range is developed. On the basis of the results obtained, some technical decisions are suggested which allow decreasing transmission dynamic load and a new type damper designs of different models are developed. It allows taking resonant modes out of the engine rpm speed working range, thus creating the conditions of increasing transmission elements durability.
2015-01-14
Technical Paper
2015-26-0032
Raimund Ellinger, Edoardo Morra, Steffen Daum, Johannes Schauer, Gebhard Woentner
Abstract Best fuel efficiency is one of the core requirements for commercial vehicles in India. Consequently it is a central challenge for commercial vehicle OEMs to optimize the entire powertrain, hence match engine, transmission and rear axle specifications best to the defined application. The very specific real world driving conditions in India (e.g. traffic situations, road conditions, driver behavior, etc.) and the large number of possible commercial powertrain combinations request an efficient and effective development methodology. This paper presents a methodology and tool chain to specify and develop commercial powertrains in a most efficient and effective way. The methodology is based on the measurement of real world driving scenarios, identification of representative Real World Driving Profiles and vehicle system simulation which allows extended analysis of the road topography, the traffic situation as well as the driver behavior.
2015-03-30
Technical Paper
2015-01-0098
Suresh Kumar Kandreegula, Naveen Sukumar, Sunil Endugu, Umashanker Gupta
Abstract Advanced Non-linear topology optimization methods have been addressed as the most promising techniques for light weight and performance design of Powertrain structures. The theoretical achievements are obtained both mechanically and mathematically. Nowadays, the great challenge lies in solving more complicated engineering design problems with multidisciplinary objectives or complex structural systems. The purpose of this paper is to provide a forum to present new developments in structural Non-linear topology optimization. The advantage of the proposed method is that structural optimization on irregular design domains can be carried out easily. Furthermore, this method integrates the stress analysis and the boundary evolution within the framework of finite element methods. In this paper, mainly focused on the Commercial Vehicles Powertrain component i.e. Transmission Housing.
2015-03-30
Technical Paper
2015-01-0088
Suresh Kumar Kandreegula, Naveen Sukumar, Sunil Endugu, Umashanker Gupta
Abstract To compete with the current market trends there is always a need to arrive at a cost effective and light weight designs. For Commercial Vehicles, an attempt is made to replace existing Gear Shift Fork from FC Iron (Ferro Cast Iron) to ADC (Aluminum Die Casting) without compromising its strength & stiffness, considering/bearing all the worst road load cases and severe environmental conditions. ADC has good mechanical and thermal properties compared to FC Iron. Feasible design has been Optimized within the given design space with an extra supporting pad for load distribution. Optimization, Stiffness, Contact pattern has been done using OptiStruct, Nastran & Ansys for CAE evaluation. A 6-speed manual transmission is used as an example to illustrate the simulation and validation of the optimized design. Advanced linear topology optimization methods have been addressed as the most promising techniques for light weighting and performance design of Powertrain structures.
2015-04-14
Technical Paper
2015-01-0517
Masaaki Kawahara, Noriaki Katori, Tatsuya Koyama
Abstract The friction pattern on the chamfers of sleeves and dog gears is a combination of peeling and adhesive wear caused by the formation and propagation of fine cracks. The effect of additional elements on wear were checked by making a test apparatus capable of performing evaluations on test pieces equivalent to those using actual parts. The results showed that the addition of B, Ti-Nb helped improve wear resistance. This is attributed to enhanced toughness and reduced peeling due to the formation of a texture. A 45% reduction in wear was achieved in actual parts tests on steel with added B, Ti-Nb.
2014-09-30
Technical Paper
2014-36-0144
Luiz Bellatini, Demetrio Vettorazzo, Carlos Barbosa, Paulo Falcone, Carlos Sena, Josevaldo Fernandes
Abstract The purpose of this paper is to provide an overview about rowing clunk on RWD MT transmissions for pick-up trucks through means of sound pressure, case acceleration and torsional vibration. Intended to identify the proper synchronizer design features necessary for its prevention. This paper will introduce the rowing clunk phenomena and present the driving maneuvers executed to reproduce the noise. The process of analysis and the phenomena composition based on simulations results, noise measurements and vibration analysis. The objective is to share with Product Engineering community an approach for Rowing Clunk Noise mitigation on Pick-up Trucks.
2016-09-27
Technical Paper
2016-01-8067
Suresh Kumar Kandreegula, Kamal Rohilla, Gaurav Paliwal, Naveen Sukumar, Naveen Pratap Tripathi
Abstract 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. There are multiple gear selector mechanisms that are available for use in commercial vehicle industry.
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