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Viewing 1 to 30 of 1184
2013-09-24
Technical Paper
2013-01-2380
Anandan Sivakumar, Sachin Wagh, G. Raghavendra, Chaitanya Govind Kulkarni, Hemant Malekar
Success of the vehicle in the market depends on comfort provided while usage, which also includes noise, vibration and harshness (NVH). In order to achieve comfort level, the NVH levels have to be as low as possible. Powertrain is the main source of NVH, in which internal combustion engine consists of crank shaft and balancer shaft. Crank shaft gear is connected and driven by crank shaft and balanced by integral eccentric mass coupled with gear. Balancer shaft is used for additional balancing of rotating masses. Pair of crank shaft and balancer shaft gears generates noise and vibration when unbalance in the system and backlash in the gears increase while usage. The practice of interposing a vibration isolator on the surface of gear has been so far resorted for preventing transmission of vibration, therefore reduction in noise. In the work presented, balancer gear was made with sandwich design to reduce noise. Sandwich design comprises of Inner hub and outer ring with lug projections.
2013-09-24
Technical Paper
2013-01-2349
Naseem A. Daher, Monika Ivantysynova
Modern on-road vehicles have been making steady strides when it comes to employing technological advances featuring active safety systems. However, off-highway machines are lagging in this area and are in dire need for modernization. One chassis system that has been receiving much attention in the automotive field is the steering system, where several electric and electrohydraulic steering architectures have been implemented and steer-by-wire technologies are under current research and development activities. On the other hand, off-highway articulated steering vehicles have not adequately evolved to meet the needs of Original Equipment Manufacturers (OEM) as well as their end customers. Present-day hydrostatic steering systems are plagued with poor energy efficiency due to valve throttling losses and are considered passive systems relative to safety, adjustability, and comfort.
2013-09-24
Technical Paper
2013-01-2347
Mikko Huova, Matti Linjama, Kalevi Huhtala
Hydraulic systems are widely used in working actions of mobile machines. They offer good power to weight ratio, robustness and relatively good controllability. However, there has been growing interest on the energy efficiency of such machines during recent years. Load sensing proportional valve control is a typical solution for multi-actuator systems leaving a significant margin for improvement of energy efficiency. Digital hydraulic valve system enables independent metering and reduces losses significantly without a need of complete redesign of the hydraulic system of such machine. Digital hydraulic valve system consists of parallel connected on/off-valves and offers deterministic operation which is crucial for successful implementation of independent metering. Four different digital hydraulic valve control approaches are analyzed in the paper: four-edge-control, four-edge control with pressurized tank line, five-edge-control and six-edge-controlled three-chamber-cylinder.
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.
2004-10-26
Technical Paper
2004-01-2673
Jean-Claude Ossyra, Monika Ivantysynova
A new control concept was developed to minimize the power losses of a hydrostatic drive line for off-road vehicles. The drive line control concept is based on two separate closed loop controls, one for the hydrostatic transmission and another for the combustion engine. The command values for both control loops are calculated under consideration of the characteristic curves of the combustion engine and the losses within the hydrostatic transmission, using an on-line optimization procedure. This paper discusses the benefits of this control concept based on a comparison of typical realistic driving manoeuvres. Objective of the investigations for different output powers is the potential of fuel savings under different operating conditions. A hardware-in-the-loop test rig for the investigated hydrostatic propel drive is used for the experimental validation.
2004-10-26
Technical Paper
2004-01-2688
Dogan San, Ergun Guraslan, Omer Rustu Ergen, Korhan Kanar
FORD OTOSAN has developed a new heavy-duty diesel engine, ECOTORQ, for the new Ford Cargo Trucks whose production started in September 2003. The engine is 7.3 liters, 6-cylinder in-line, with common rail fuel injection system and overhead camshaft design having 4 valves per cylinder. The engine meets the Euro-III exhaust emissions limits, which were in effect when it was introduced, and the engine incorporates the potential to meet Euro-IV. Modern computation and simulation methods were used and extensive experimental studies were made during the design and development stages, which helped reach the targets of compactness, modular structure, low fuel consumption, low noise level and low emissions.
2004-10-26
Technical Paper
2004-01-2724
Murali M. R. Krishna, Jun Yoshioka, Manish Sharma
A web based software program has been developed to do a Finite Element (FE) analysis of a simplified driveline system. In the past, an expert analyst had to make a Finite Element Model, analyze and then report results. It has been observed that this process is time consuming besides the difficulties of doing quick parametric studies, geographical location of designers, analysts, etc. The web-based software program aims to solve these issues. The designer could get analytical & Finite element results anywhere around the world (where the designer has access to the web) without any expertise in FE modeling. This software is a joint effort of Engineering and Information Technology (IT) software groups. It is based on Active Server Page (ASP) technology and MSC/NASTRAN technologies combined. Input data deck is prepared from user inputs and submitted over the internet to a remote system, solved and results are retrieved and plots shown in minutes, instead of days earlier.
2004-10-26
Technical Paper
2004-01-2687
Paul G. Evans, Kevin Johanson
This paper describes a radical new approach to variable flow oil pump design, which addresses some concerns of earlier designs and also conventional fixed displacement pumps. Detailed here are the testing and results to date, the potential areas for the future work, together with the reduction in parasitic power loss and potential fuel consumption savings. Also discussed are the benefits that can be realised by using this product as a tool for radically changing current automotive lubrication systems.
2004-10-26
Technical Paper
2004-01-2647
Douglas A. Swift, Carl Talaski
A sensor system was developed to measure loads in truck wheels. The system has the unique capability to measure each individual wheel in a dual set. This paper covers the development and testing of the system. Sample data from road tests is also presented.
2004-10-26
Technical Paper
2004-01-2668
Hannes Hick, Klaus Denkmayr, Michael Aschaber
The AVL Load Matrix is a systematic approach to optimize durability and reliability test programs. It is based on component-specific test acceleration factors and uses damage models as well as statistics. Using the Load Matrix approach helps to achieve complete test programs while avoiding unrealistic over-testing. The paper describes the Load Matrix concept and structure as well as the process of setting up the Load Matrix for a system or component. Examples are provided on damage models, and the procedure to estimate the acceleration factors is discussed.
2004-10-26
Technical Paper
2004-01-2667
Timothy J. Milburn
Product development and manufacturing organizations are moving from the traditional, multiple and serial design-build-test cycle approach to an integrated, concurrent task and systems engineering paradigm, led by upfront planning, analysis and simulation, supported by credible product test data. This “paradigm shift” includes a move from a predominance of physical testing for product prototype validation to simulation-led problem solving and performance validation, using Computer Aided Engineering, and Design (CAE and CAD) tools. Supported by use of Computer Aided Testing (CAT), physical testing capabilities have comparably grown in accuracy and application range. The role of testing is moving from mostly pre-production validation to include support of product design decisions throughout the development process, including upfront planning.
2004-10-26
Technical Paper
2004-01-2656
Luciano Caletti, Jonny Carlos da Silva
This paper describes the development of an expert system project to design hydraulic power supply units, known as PHIDR, which is considered a natural expansion of KEOHPS Hydraulic Module. The expert system aims to support the designer in the process of selecting, in an efficient manner, the most adequate power supply unit based on design requirements and best practice rules. The text presents a description of the prototype system as well as its development process, including knowledge acquisition, representation, implementation and validation. Future issues on system expansion are also discussed.
2004-10-26
Technical Paper
2004-01-2705
Jeffrey R. Stokes, Paul W. Claar
Data envelopment analysis (DEA) is used to examine the efficiency of 74 front wheel assist agricultural tractors from three U.S. manufacturers. The outputs of drawbar horsepower and power takeoff horsepower are modeled in a constant returns-to-scale framework using three productive performance inputs (fuel consumption, slip, and center of gravity), and one price input, namely, retail tractor price. The results suggest that by and large, John Deere tractors are more DEA efficient than their competitor's tractors. However, competitor's tractors that are DEA efficient are most often the top benchmarks for DEA inefficient tractors. These results suggest that while John Deere appears to produce many quality tractors, competitor's like CNH and AGCO produce a few tractors that may be of even higher quality.
2004-10-26
Technical Paper
2004-01-2655
Robert Rahmfeld, Monika Ivantysynova, Bastian Eggers
This paper deals with the use of a displacement controlled linear actuator for active oscillation damping of off-road machine structure. Aim is the development of system solutions and control concepts for the simultaneous use of displacement controlled (valveless) hydraulic actuators basing on single rod cylinder for the active oscillation damping of off-road machine structure and for the control of the working hydraulics movement. Thereby, the productivity of the machine and the operator comfort will be improved.
2004-10-26
Technical Paper
2004-01-2706
Kenji Kato, Satoshi Machida, Masao Takagi, Keishiro Nishi
1. ABSTRACT The New Kubota Grand L30 Series Compact Tractors are powerful, user-friendly compact tractors that have advanced functions to provide the maximum performance. Many new features such as IntelliPanel enable users to obtain high workability, comfort, and operability. IntelliPanel is an advanced function that displays information on a liquid crystal display to help users' with operation and maintenance. An electronically controlled multi-gear GST (Glide Shift Transmission) enables users to choose gears for 12 travel speeds using one lever, during travel without operating a clutch. An ECU (Electric Control Unit) controls solenoid valves and a proportional reducing valve to allow for smooth gear changes.
2004-10-26
Technical Paper
2004-01-2707
Rosca Radu, Rakosi Edward, Manolache Gheorghe
The paper attempts to determine which traction model best fits with experimental data for a romanian lugged tractor tire. Different models for predicting net traction and traction efficiency for off-road conditions were considered. These models assume different tire-ground pressure distributions (constant, parabolic) over the undertread area and different contact patch length calculations. Experiments were conducted and the results were compared to the theoretical data. Two of the models are the best fit with the experimental data; both models assumed a parabolic pressure distribution over the undertread.
2004-03-08
Technical Paper
2004-01-1768
Wolfram Hohmann
In this paper we will explore how 15 years after being introduced into avionics systems, “by-wire” technologies have entered the automotive world. The use of software within safety-relevant application areas like restraint systems, braking, steering and vehicle dynamics support and control systems, is requiring changes in the processes and methodologies used for embedded software development.
2013-01-09
Technical Paper
2013-26-0100
J. Sai Prasad, N. Chollangi Damodar, T. Sudhakara Naidu
The acceptable noise and vibration performance is one of the most important requirements in a passenger bus as it is intended for widest spectrum of passengers covering all age groups. Gear rattle, being one of the critical factors for NVH and durability, plays a vital role in passenger comfort inside vehicle. The phenomenon of gear rattle happens due to irregularity in engine torque, causing impacts between the teeth of unloaded gear pairs of a gearbox which produce vibrations giving rise to this unacceptable acoustic response. In depth assessment of the dynamic behavior of systems and related components required to eliminate gear rattle. During normal running conditions, abnormal in-cab noise was perceived in a bus. Initial subjective evaluation revealed that the intensity was high during acceleration and deceleration. Objective measurements and analysis of the in-cab noise and vibration measurements had indicated that the noise is mainly due to gear rattling.
2013-01-09
Technical Paper
2013-26-0111
Parul Goyal, Gaurav Chaudhary, Nirmal N
A two-stage spool valve system is common in the hydraulic system of an off-road vehicle and used as hydraulics control element for controlling the hydraulic cylinder. Off-road vehicle industries mostly use a fixed-gain PID based controller for the flow control of the two-stage spool valve system. A hydraulic spool valve system exhibits highly nonlinear behavior, which makes it challenging to design a PID based controller to control its dynamics. This paper presents a method for the dynamic system model development of the two-stage spool valve system. This model will be useful to study the impact on the valve dynamics due to lubricating oil properties variation to avoid the potential system hazards and machine failure scenarios. An alternative control system design approach is also proposed based on the gain-scheduled control technique, wherein the non-linear dynamics of the valve system is linearized at different equilibrium points and PID gains are scheduled at these points.
2013-01-09
Technical Paper
2013-26-0145
S. Narayanan, S. Mithun, T. Sahul Hameed
A lift axle suspension system in a heavy commercial vehicle enables raising and lowering of the lift axle depending on the vehicle load condition. The states (raising and lowering) of the axle will be in logical sequence which depends on the vehicle load, ignition state, gear state and traction requirement. To arrive this complicate logic, the Lift Axle Control valve is designed. This LACV is an intricate assembly of pneumatic 3/2 valve, 5/2 valve, relay valve and solenoid valves. To predict the performance of this valve under various vehicle conditions, the entire valve is modeled in one of the commercially available multi-domain physical modeling software employing bond graph technique and lumped system and the performance is predicted. This paper deals with the modeling of LACV, simulation of misbehavior of LACV under certain condition, and the design analysis carried out to arrive design solution.
2013-01-09
Technical Paper
2013-26-0150
Jeevan N. Patil, Sivakumar Palanivelu, Ajit Kumar Jindal
Air brake system is widely used in heavy duty trucks and buses due to its great performance and efficiency. Dual brake valve (DBV) is one the of major and crucial component of an air brake system as it is controlling the air flow from reservoir to brake chamber during braking operation. Currently, due to its own complexity, it is very difficult for designer to optimize different parameters. As experimentation is tedious and time consuming task, hence it is very important to have mathematical model of DBV during in early design stage. Differential equations have been formulated for individual component of DBV such as primary piston, primary valve, relay piston, and relay valve etc. system level mathematical model has been formulated and implemented in Matlab/Simulink to capture the dynamic pressure characteristic of DBV. At the same time mathematical model of DBV has been created in AMESim to check the validity of approach.
2013-01-09
Technical Paper
2013-26-0153
Prashant R. Pawar, Yogesh V. Dhage, M. R. Saraf, Vratislav Ondrak
The demands for safe, reliable, lighter, energy efficient and competitively priced products put a new emphasis on predictability of rolling bearing performance. This has prompted designers and engineers to estimate bearing life and optimize the design by taking into account different market requirement. Estimation of actual dynamic bearing load and life for specified class of vehicle depends upon various factors such as usage pattern, vehicle Gross Vehicel Weight (GVW), type of roads, speed, driving pattern, geographical area, ambient temperature, acceleration etc. For estimation and prediction of life of the particular wheel bearing type it is required to identify and measure customer usage loads for different targeted markets. The measurement maps all the affecting parameters to arrive at a generalized duty cycle for bearings.
2014-04-01
Journal Article
2014-01-1018
Robert V. Petrach, David Schall, Qian Zou, Gary Barber, Randy Gu, Laila Guessous
Coatings have the potential to improve bearing tribological performance. However, every coating application process and material combination may create different residual stresses and coating microstructures, and their effect on bearing fatigue and wear performance is unclear. The aim of this work is to investigate coating induced residual stress effects on bearing failure indicators using a microstructural contact mechanics (MSCM) finite element (FE) model. The MSCM FE model consists of a two-dimensional FE model of a coated bearing surface under sliding contact where individual grains are represented by FE domains. Interactions between FE domains are represented using contact element pairs. Unique to this layered rolling contact FE model is the use of polycrystalline material models to represent realistic bearing and coating microstructural behavior. The MSCM FE model was compared to a second non-microstructural contact mechanics (non-MSCM) model.
2013-10-07
Technical Paper
2013-36-0154
Rafael V. Carvalho, Ludmila C. A. Silva, Milton Amaro, Alessandro A. Ferreira, Aparecido M. da Rosa
Heating generation in rolling bearings is a critical point for development and application, specially for heavy trucks. Several problems can occur in the rolling bearing and in the system when the temperature increases. For example, at high temperature levels the rubber sealing can change its proprieties and volume, creating a high interference at the contact with the rings. The grease can also be affected and modify its viscosity, generating a possible leakage, which is not allowed during life. This papers aims to study the heat generation and evaluate, experimentally, the temperature stabilization in clutch release bearings for heavy duty application. With this purpose, several tests were performed and the results were analyzed to find the main factors that can be influenced.
2013-10-07
Technical Paper
2013-36-0605
Fabio B. Bassetti
Modern diesel engines for vehicular applications such as buses and other commercial vehicles are increasingly using technological resources in order to meet the pollutant emissions regulations. Among these features, the turbocharger fulfills an essential function of providing a higher air flow to the engine intake, providing a cleaner and more efficient combustion. During the application process of a turbocharger, calculations are performed to estimate the life of the compressor impeller, which takes into account the maximum shaft speed and the number of cycles that cause fatigue damage. Among these parameters, the maximum speed affects directly in the fatigue life of the impeller. Due to the different material options for the compressor impeller, the mass properties of each type of rotor may result in differences in their inertias thus impacting the maximum speed and the fatigue life calculation.
2011-04-12
Technical Paper
2011-01-1382
Wenbin Yu, Bin Liu, Yang Li, Qingpeng Su, Yiqiang Pei, Wanhua Su
Combustion control strategy for high efficiency and low emissions in a heavy duty (H D) diesel engine was investigated experimentally in a single cylinder test engine with a common rail fuel system, EGR (Exhaust Gas Recirculation) system, boost system and retarded intake valve closing timing actuator. For the operation loads of IMEPg (Gross Indicated Mean Effective Pressure) less than 1.1 MPa the low temperature combustion (LTC) with high rate of EGR was applied. The fuel injection modes of either single injection or multi-pulse injections, boost pressure and retarded intake valve closing timing (RIVCT) were also coupled with the engine operation condition loads for high efficiency and low emissions. A higher boost pressure played an important role in improving fuel efficiency and obtaining ultra-low soot and NOx emissions.
2011-05-17
Technical Paper
2011-01-1531
Michael Thivant, pascal BOUVET PhD, Alexandre Carbonelli
Due to the increasing focus on noise and vibration for future vehicles, there is a need for a clear definition of the requirements between vehicle manufacturers and auxiliary suppliers. Auxiliary characterisations are also needed as input for structure-borne numerical prediction models. Strongly coupled systems are amongst the most difficult structure-borne noise issues, as the transmitted forces and powers are strongly dependent upon the mobilities of both the vibration source and receiver. The so-called “blocked forces” can be used as intrinsic source descriptions. The challenge is then to design auxiliary test benches perfectly rigid in the frequency range of interest. The current paper is based on the French research program MACOVAM dedicated to the vibro-acoustic characterisation of oil pumps for truck engines. An original test bench was designed to measure quasi-blocked forces over the [150 Hz-2800 Hz] frequency range.
2011-09-13
Journal Article
2011-01-2272
Wolfgang Schweiger, Werner Schoefmann, Andrea Vacca
This paper presents a simulation model for the analysis of internal gear ring pumps. The model follows a multi domain simulation approach comprising sub-models for parametric geometry generation, fluid dynamic simulation, numerical calculation of characteristic geometry data and CAD/FEM integration. The sub-models are interacting in different domains and relevant design and simulation parameters are accessible in a central, easy to handle graphical user interface. The potentials of the described tool are represented by simulation results for both steady state and transient pump operating conditions and by their correlation with measured data. Although the presented approach is suitable to all applications of gear ring pumps, a particular focus is given to hydraulic actuation systems used in automotive drivetrain applications.
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.
2011-05-17
Technical Paper
2011-01-1604
Zhi-yong Chen, Guang-ming Wu, Wen-ku Shi, Qing-guo Wang, Teng Teng
Hyperelastic model constants of rubber material are predicted based on test date. The fluid-structure interaction model of light vehicle cab's hydraulic mount is established. Static characteristics of the hydraulic mount are analyzed by quasi-static method. In dynamic characteristics analysis, the flow model of fluid is set to turbulent K-Epsilon RNG. The dynamic stiffness and loss angle of the hydraulic mount are presented via the finite element model. The simulations of static and dynamic characteristics agree well with corresponding test results. The effects of main structure parameters to the dynamic characteristics of the hydraulic mount are analyzed based on the finite element model.
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