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Viewing 121 to 150 of 6758
2016-11-08
Journal Article
2016-32-0024
Daisuke Sugio, Shinpei Okazaki, Mitsuo Kaneko
Abstract Glass fiber reinforced plastic of polyamide is applied as one of the materials used for the high strength exterior parts of a motorcycle, such as a rear grab rail or a carrier, to which both strength and good exterior appearance are required. However, Glass Fiber reinforced Polypropylene (PPGF), which is relatively inexpensive material, has a property that the contained glass fibers are prone to be exposed at the surface and, therefore, the requirements for good appearance are hardly met by using PPGF. In this study, Heat and Cool molding method (H&C molding) was employed to realize a cost reduction by using PPGF yet without applying painting process, and the established method was applied to mass production while fulfilling the requirements for a good exterior appearance. In H&C molding, the metal molds are heated up by steam and cooled down by water after molding.
2016-10-28
Technical Paper
Parts and Components
2016-10-25
Technical Paper
2016-36-0134
Levi N. da Silva, Kerolin F. Tessari, Maicon D. Garcia, Thiago C. de Freitas
Abstract Experimental results reveal that the temperature rise of two contacting bodies in relative sliding motion is related to increase of torque and loads caused by expansion of bearing components. The evolution of effects of thermally induced loads with time in an angular contact ball bearing in a controlled temperature environment is studied experimentally and analytically. The test apparatus is an axially-loaded angular contact ball bearing instrumented to measure the dynamic frictional torque as well as the transient temperature of the raceway and environment inside of a chamber with controlled temperature. Effects of friction torque were examined at different speeds, operating temperatures and pre-loads. The mathematical model developed provides a comprehensive thermal analysis of the ball bearing with provision for frictional heat generation, heat transfer processes and thermal expansion of bearing components.
2016-10-25
Technical Paper
2016-36-0170
Moisés Krutzmann, Dimitrius Caloghero, Tiago Schmidt, Rogério Marczak
Abstract The knowledge of mechanical behaviour of material is vital for durability prediction and attending initial project requirements. Through the experimental evaluations is possible to measure this behaviour and use it as input in numerical simulations. Temperature changes considerably static and dynamic mechanical properties of materials, particularly in elastomers. This study was motivated to predict the durability under several working temperatures of center bearings rubber cushion of driveshafts that needs to achieve prespecified stiffness and durability parameters. Standardized specimens were tested in fatigue for experimental investigation of the rubber compound. Durability tests were performed in the final product sample and compared with tests performed in standardized specimens. It was concluded that this approach produces accurate results for fatigue predictions and provided useful equations for practical design applications and reducing product validation time.
2016-10-25
Technical Paper
2016-36-0423
Bruno Barbosa Salles, Almir Atoatte, Robson Cruz
Abstract Targeting the current demands for engines with lower emissions, reduced fuel consumption, downsizing and higher peak combustion pressures, thyssenkrupp has developed a new cranktrain concept comprising an increased radial transition between journal and web that extends itself into the bearing’s load-carrying zone, creating a symmetrical U-shaped profile. The resulting non-straight bearing contour restricts the use of a standard bearing shell and led to the development of an integral bearing solution, where a copper based material was applied directly to the connecting rod big end bore. The so-called U-shape cranktrain was experimentally evaluated on a fired engine through a series of eight test steps with varied loads and speeds, being each step condition defined in a way that increased severity was applied to the connecting rod bearings as the test proceeded. The engine was disassembled after each step for analysis and measurement of the crankshaft and connecting rods.
2016-10-17
Technical Paper
2016-01-2189
Bo Wang, Tawfik Badawy, Yanfei Li, Hongming Xu, Yizhou Jiang, Xinyu Zhang
Abstract Atomization of fuel sprays is a key factor in controlling the combustion quality in the direct-injection engines. In this present work, the effect of saturation ratio (Rs) on the near nozzle spray patterns of ethanol was investigated using an ultra-high speed imaging technique. The Rs range covered both flash-boiling and non-flash boiling regions. Ethanol was injected from a single-hole injector into an optically accessible constant volume chamber at a fixed injection pressure of 40 MPa with different fuel temperatures and back pressures. High-speed imaging was performed using an ultrahigh speed camera (1 million fps) coupled with a long-distance microscope. Under non-flash boiling conditions, the effect of Rs on fuel development was small but observable. Clear fuel collision can be observed at Rs=1.5 and 1.0. Under the flash boiling conditions, near-nozzle spray patterns were significant different from the non-flash boiling ones.
2016-10-17
Technical Paper
2016-01-2202
Naoya Ochiai, Jun Ishimoto, Akira Arioka, Nobuhiko Yamaguchi, Yuzuru Sasaki, Nobuyuki Furukawa
Abstract The advanced development and optimization of fuel atomization in port and direct injection systems for automobile engine is desired for the improvement of fuel combustion performance and thermal efficiency of the engine. Computational prediction and design of injector nozzle spray flow is an effective method for that. However, a practical simulation method of the continuous primary, secondary spray breakups and the spraying behavior have not been developed yet. In this study, we have developed the integrated computational method of the total fuel atomization process of the injector nozzle. This new computational approach is taking into account the nozzle internal flow to form the primary breakup using Volume of Fluid (VOF) method in connection with the spray flow characteristics to the engine cylinder using Discrete Droplet Model (DDM).
2016-10-17
Technical Paper
2016-01-2345
Guoyu Feng, Wenku Shi, Henghai Zhang
Abstract In order to study the static and dynamic characteristics of the thrust rod. Based on the multi-body dynamics theory, the dynamic model of the thrust rod and the vehicle system is established by using ADAMS software. The limit braking condition is simulated, and the limit braking load of the thrust rod is obtained. Thrust rod finite element model is established, the load calculation value and rubber test data as a finite element analysis of input conditions, using ABAQUS software to carry on the stiffness and strength analysis, analysis results show that the strength meets the requirement, and the stiffness and strength calculation result is in good agreement with the sample test, accurately describes the finite element model. The analytical method used can be used to predict the stiffness of the thrust rod.
2016-10-17
Technical Paper
2016-01-2272
Carl Bennett, Jason Bell, Jeffrey Guevremont
Abstract Elastomer compatibility is an important property of lubricants. When seals degrade oil leakages may occur, which is a cause of concern for original equipment manufacturers (OEMs) because of warranty claims. Leakage is also a concern for environmental reasons. Most often, the mechanical properties and fitting of the oil seals is identified as the source of failure, but there are cases where the interaction between the lubricant and the seal material can be implicated. The performance of seal materials in tensile testing is a required method that must be passed in order to qualify lubricant additive packages. We conducted an extensive study of the interactions between these elastomeric materials and lubricant additive components, and their behavior over time. The physicochemical mechanisms that occur to cause seal failures will be discussed.
2016-10-17
Journal Article
2016-01-2204
Takafumi Mori, Masanori Suemitsu, Nobuharu Umamori, Takehisa Sato, Satoshi Ogano, Kenji Ueno, Oji Kuno, Kotaro Hiraga, Kazuhiko Yuasa, Shinichiro Shibata, Shinichiro Ishikawa
Abstract Torque loss reduction at differential gear unit is important to improve the fuel economy of automobiles. One effective way is to decrease the viscosity of lubricants as it results in less churning loss. However, this option creates a higher potential for thin oil films, which could damage the mechanical parts. At tapered roller bearings, in particular, wear at the large end face of rollers and its counterpart, known as bearing bottom wear is one of major failure modes. To understand the wear mechanism, wear at the rolling contact surface of rollers and its counterpart, known as bearing side wear, was also observed to confirm the wear impact on the tapered roller bearings. Because gear oils are also required to avoid seizure under extreme pressure, the combination of a phosphorus anti-wear agent and a sulfurous extreme pressure agent are formulated.
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.
2016-09-27
Technical Paper
2016-01-8062
Jham Kunwar Tikoliya, Ram Krishna Kumar Singh, Ramesh Kumar, Suresh Kumar Kandreegula
Abstract The existing head cover is having external oil and blow by separation unit, which is not only costlier but also complex and leads to increase in overall height of engine which was difficult to integrate in new variants of vehicles. A new head cover has been designed with internal baffle type oil and blow by separation system to ensure efficient separation and proper packaging of the system in new variants. The new system has been finalized after 26 DOE’s of different wire mesh sizes and different baffle plate size and positions. The final system has two bowl shaped separation unit with wire mesh, two cup type oil separation passages and one baffle plate for separating blow by. The system works on condensation and gravity method. The blow by is guided through a well-defined passage integrated in aluminum cylinder head cover itself. The passage angle is maintained to ensure minimum oil flow with blow by.
2016-09-27
Technical Paper
2016-01-2079
Alexander Janssen, Thorsten Dillhoefer
The industry wide requirement of new highly flexible automated fastening systems in aircraft production has created the need for developing new fastening systems. This paper will focus on the development of the Frame Riveting Assembly Cell (FRAC) by BROETJE-Automation to meet this need. The new FRAC machine configuration is built for automated drilling and fastening of different aircraft type parts. It is highly flexible with a high speed positioning system mounted multifunction end effector. System travel is limited only by installed track length. The FRAC integrates well with conventional and reconfigurable automated fastening work holding tools.
2016-09-27
Journal Article
2016-01-2081
Rodrigo Pinheiro, Robert Gurrola, Sead Dzebo
Abstract The installation of common threaded aerospace fasteners by the application of a torque to a nut or collar is made possible by an internal wrenching element or recess feature adapted to the threaded end of a pin, which accepts a mating anti-rotation key designed to partially balance the applied torque. In applications such as the mechanical joining of composite structures accomplished by wet clearance fit installations of permanent fasteners, high nut or collar seating torques not adequately opposed by frictional resistance at the contact surfaces of the fastener and joint members effectively shift a greater proportion of the torque reaction requirement onto the recess and mating anti-rotation key which in turn can experience high torsional stresses exceeding their design capability and result in frequent service failures.
2016-09-27
Technical Paper
2016-01-2083
Steven P. Smith
Abstract This paper traces the development of a temporary blind fastener in the aircraft industry. These are used with automated drilling machines as part of an integrated assembly process where one-way assembly is inappropriate. Traditional blind temporary fasteners have a high protrusion (stand-off) on the side they are installed from, effectively preventing automated drilling. No suitable fastener was available on the market and existing suppliers were uninterested in development at the time. A set of requirements were created out of the need to improve efficiency of A380 wing assembly. However focus changed as the A350XWB programme demanded such a fastener. Testing, development and Stress approval are described leading to full deployment. Finally the paper looks at the additional factors which are required to successfully introduce a new standard of temporary fastening process.
2016-09-27
Journal Article
2016-01-2085
Kyle Pritz, Brent Etzel, Zheng Wei
The automation cycle time of wing assembly can be shortened by the automated installation of single-sided temporary fasteners to provide temporary part clamping and doweling during panel drilling. Feeding these fasteners poses problems due to their complexity in design and overall heavy weight. In the past, Electroimpact has remotely fed these fasteners by blowing them through pneumatic tubing. This technique has resulted in occasional damage to fasteners during delivery and a complex feed system that requires frequent maintenance. Due to these issues, Electroimpact has developed a new fully automated single-sided temporary fastening system for installation of the LISI Clampberry fasteners in wing panels for the C919 wing factory in Yanliang, China. The feed system stores fasteners in gravity-fed cartridges on the end effector near the point of installation.
2016-09-27
Technical Paper
2016-01-2089
Jose Guerra cEng, Miguel Angel Castillo
Abstract Aernnova experience on automatic drilling operations started in 1,999. The company signed a new contract with Embraer, to design, manufacture and assembly several structures of the model 170. It was big news for the company. But after that minute of pride, manufacturing engineering people of the company started to think about the process to assemble those big panels of the Horizontal Stabilizer, Vertical Stabilizer and Rear Fuselages in the best Quality and Cost. There were a lot of rows of rivets to install. Some ideas arisen, but the final decision was to forget the available processes at that time and think about to automate the drilling, countersink and riveting of the stringers, doublers and window frames to the panels. There were a lot of doubts, figures to do and obstacles, but the company took the decision of going ahead with that process. That step changed the state of the art at that time in the company.
2016-09-27
Technical Paper
2016-01-2145
Ryan Haldimann
Abstract Inspection of fasteners prior to installation is critical to the quality of aerospace parts. Fasteners must be inspected for length/grip and diameter at a minimum. Inspecting the fasteners mechanically just prior to insertion can cause additional cycle time loss if inspection cannot be performed at the same time as other operations. To decrease fastener inspection times and to ensure fastener cartridges contain the expected fastener a system was devised to measure the fastener as it travels down the fastener feed tube. This process could be adapted to inspection of fasteners being fed to the process head of a running machine eliminating the mechanical inspection requirement and thus decreasing cycle time.
2016-09-27
Technical Paper
2016-01-2128
Henry Guo, Farid Ahdad, DeDong Xie
Abstract In this work we have proposed an interesting clamping solution of V-band which has an important industrial impact by reducing the cost and assembly process as well compare to the traditional V-band. The design what we are focusing for is applied for all size of turbochargers which helps to connect the hot components such as manifold and turbine housing. The cost for V-band is mainly from T-bolt. It is made from special stainless steel which represents 50% of the total cost. In this work it is proposed a new V-band joint by changing bolt clamping status from tension to compression. From tension to compression we change the bolt material from high cost steel to low cost steel. The new total cost is reduced by 40%. The prototype is made and performed in static tests including anti-rotating torque test and salt spray test. The new joint meets the design requirements at static condition. Further work will focus on the dynamic qualification and at high temperature as well.
2016-09-27
Journal Article
2016-01-2080
Carter L. Boad, Kevin Brandenstein
The newest generation of automated fastening machines require a feed system that is smaller, more flexible, and faster than any currently available. The feed system must be compact enough to fit on a robot base, yet have a capacity large enough to support unmanned production for hours. A large variety of fasteners must be supported and the entire system must be reloaded or reconfigured in minutes to match the next work piece being assembled by the machine. When requested by the part program, the correct fastener must be released directly and immediately into the feed tube to minimize cycle time. This paper describes a new “plate cartridge” feed system developed to meet these needs.
2016-09-27
Technical Paper
2016-01-2084
Curtis Hayes
Abstract Successfully riveting aerospace fatigue-rated structure (for instance, wing panels) requires achieving rivet interference between a minimum and a maximum value in a number of locations along the shank of the rivet. In unbalanced structure, where the skin is much thicker than the stringer, this can be particularly challenging, as achieving minimum interference at the exit of the skin (D2) can often be a problem without exceeding the maximum interference at the exit of the stringer (D4). Softer base materials and harder, higher-strength rivets can compound the problem, while standard manufacturing variations in hardness of part and rivet materials can cause repeatability issues in the process. This paper presents a solution that has been successfully implemented on a production commercial aircraft.
2016-09-27
Technical Paper
2016-01-2098
Christophe Vandaele, Didier Friot, Simon Marry, Etienne Gueydon
Abstract With more than 10 000 aircrafts in their order backlog Aircraft manufacturers focus on automated assembly is of critical importance for the future of efficient production assembly. Moreover to obtain maximum benefit from automation, it is necessary to achieve not only an automated assembly cell, but also a real breakthrough in fastener technology. The optimum solution, known as “One Side Assembly”, performs the whole assembly sequence from one side of the structure using an accurate robot arm equipped with a multifunction end effector and high performance fasteners. This configuration provides an efficient and flexible automated installation process, superior to current solutions which are typically, large scale, capital intensive systems, which still require operators to complete or control the fastener installation. The search for a technological breakthrough in this domain has been targeted for more than 15 years by many aircraft manufacturers.
2016-09-27
Journal Article
2016-01-8100
Jordan Kelleher, Nikhil Ajotikar
Abstract Piston cooling nozzles/jets play several crucial roles in the power cylinder of an internal combustion engine. Primarily, they help with the thermal management of the piston and provide lubrication to the cylinder liner and the piston’s wrist pin. In order to evaluate the oil jet characteristics from various piston cooling nozzle (PCN) designs, a quantitative and objective process was developed. The PCN characterization began with a computational fluid dynamics (CFD) turbulent model to analyze the mean oil velocity and flow distribution at the nozzle exit/tip. Subsequently, the PCN was tested on a rig for a given oil temperature and pressure. A high-speed camera captured images at 2500 frames per second to observe the evolution of the oil stream as a function of distance from the nozzle exit. An algorithm comprised of standard digital image processing techniques was created to calculate the oil jet width and density.
2016-09-20
Technical Paper
2016-01-2039
Prashant S. Vadgaonkar, Ullas Janardhan
Avionics industry is moving towards fly-by wire aircrafts with less reliance on mechanical systems leading to increase in the complexity of in-flight hardware elements. RTCA/DO-254 and EUROCAE ED-80 plays a vital role in the design assurance of airborne electronic hardware. RTCA/ DO-254 and EUROCAE ED-80 are the industry standards for Design Assurance Guidance for Airborne Electronic Hardware. The two different agencies FAA and EU regulate and apply this design assurance guidance to the regulatory law in CFR and EASA CS respectively. This paper discusses the need for DO-254 /ED-80 certification in Aerospace industry, the advantages and benefits to the avionics manufacturers. The paper presents the study made on similarities and differences between DO-254/ED-80.
2016-09-20
Technical Paper
2016-01-1996
David R. Markham, J. Michael Cutbirth
Abstract Modern military electronics systems are generating increasingly higher heat loads, necessitating larger capacity thermal management systems (TMSs). These high-capacity TMSs must meet the strict size and weight requirements of these advancing platforms. Commercially available compressor technology can generate sufficient cooling for these systems; however, they are too heavy and expansive. Mainstream Engineering Corporation has developed a compact, lightweight, high-speed screw compressor that can provide a large cooling capacity with a small package envelope. The compressor housing material is light-weight with a low coefficient of thermal expansion (CTE), allowing a wide operating temperature range. The compressor, with a nominal cooling capacity from 20 kW to 60 kW, was tested over a range of saturated suction conditions, pressure ratios, rotational speeds, and oil lubrication conditions.
2016-09-18
Technical Paper
2016-01-1957
Seonho Lee, Heejae Kang, Ohchul Kwon, Chirl Soo Shin
Abstract A trend in automotive parts development is the pursuit of long life, high quality and reliability. The increase in service life of automotive wheel bearings, by improving the rolling contact fatigue (RCF) life of bearing steels, was investigated. Conventional studies of bearing steels and heat treatments have dealt with quenching and tempering (Q/T) in 52100 steel. This study is a new trial to increase the strength of bearing steels by special austempering in phases after general Q/T heat treatments.
2016-09-18
Technical Paper
2016-01-1960
Yukihisa Takayama
Recently, vehicle production volumes have been increasing, particularly in newly developing countries that often lack adequate infrastructure. These regions utilize many unimproved roads and frequently experience heavy rainfall, requiring robust product features. In contrast, developed countries, with well-maintained infrastructure, have emphasized protection of the environment, requiring automobile manufacturers to target reductions in carbon dioxide emissions. Hub unit bearings, which enable smooth wheel rotation, are mounted at the wheel center. The hub bearing is a critical part which supports the automotive body and requires high reliability. To make environmental progress, hub unit bearings have increasing requirements for low friction. NSK has developed effective grease technologies to meet the diverse requirements of hub unit bearings, such as high reliability and low friction under severe environmental conditions.
2016-09-18
Journal Article
2016-01-1956
Robert G. Sutherlin, Douglas Reed
Abstract For higher mileage vehicles, noise from contaminant ingress is one of the largest durability issues for wheel bearings. The mileage that wheel bearing sealing issues increase can vary due to multiple factors, such as the level of corrosion for the vehicle and the mating components around the wheel bearing. In general, sealing issues increase after 20,000 to 30,000 km. Protecting the seals from splash is a key step in extending bearing life. Benchmarking has shown a variety of different brake corner designs to protect the bearing from splash. This report examines the effect of factors from different designs, such as the radial gap between constant velocity joint (CVJ) slinger and the knuckle, knuckle labyrinth height and varying slinger designs to minimize the amount of splash to the bearing inboard seal. This report reviews some of the bearing seal failure modes caused by splash.
2016-09-18
Journal Article
2016-01-1959
Laura Sguotti, Davide Olivieri, Domenico Bosco
Abstract Bearing friction is a direct contribution to vehicle CO2 emissions. The friction is defined as the total resistance to rotation, resulting from the combination of rolling and sliding friction in the contact areas. First, friction reduction was approached from a theoretical standpoint by employing modeling and simulation techniques. Improvements identified in simulation were then used to: create a new set of design rules for the internal geometry of the bearing, introduce a new grease, develop new seals, also with the integration of labyrinth functions and an optimization of the preload range variation. In order to provide a reliable confirmation of the expected achievements, a new friction measurement methodology was also introduced.
2016-09-18
Journal Article
2016-01-1958
Seungpyo Lee, Nahyon Lee, Jongkeun Lim, Jungyang Park
Abstract Through transmitting power and carrying vehicle weight, automotive wheel bearings play an important role. Counterbalancing the bearing responsibilities, they also are designed to last the life of a vehicle without servicing. When mounted to the vehicle steering knuckle by bolts, distortion occurs to the outer ring. Performance is affected when distortion takes place at the seal mounting location and raceways. Finite element analysis using commercial software was performed to analyze the outer ring distortion. Elasto-plastic and contact analyses were carried out to compute the clamping behavior of the outer ring, bolts and the knuckle under various conditions. To verify the reliability of this study, the distortion of the outer ring was measured. The experimental results proved to be comparative with the analysis results.
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