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Viewing 15061 to 15090 of 19492
1982-02-01
Technical Paper
821105
Donald B. Reinke
The development of the hydrodynamic and hydrostatic transmissions began within the same decade and since that time have grown to relatively widespread use. While quite different in construction they bear the common designation of a hydraulic transmission. Each transmission type has its proponents who, in many cases, do not fully understand the characteristics of the other type. Considerable controversy develops which can be abated by a better understanding of operating features with respect to operating conditions. This paper is intended to assist that analysis through a side by side comparison.
1982-02-01
Technical Paper
821104
Talkehiko Takamatsu, Tomoyuki Takahashi
Komatsu exhibited a prototype model of its 120T bulldozer, D555A, at the CONEXPO’81 in 1981. The D555A is capable of mass earth-moving with high productivity - a requirement that is growing rapidly, in recent years. Together with innovative features which provide for high machine availability, high durability, and, operational ease and low fatigue, the D555A is designed to be the forerunner of next generation bulldozers. At present the D555A is being field-tested, and will be placed on the market in the near future. Here we shall present the design concepts underlying the giant D555A, and the steps taken in achieving the essential design targets.
1982-02-01
Technical Paper
821196
D. E. Flathmann, R. F. Barker, W. S. Wylie
Three pairs of cars were each driven over 80 000 km at predominantly highway speeds and summer ambient temperatures. One car of each pair used an SAE 0W-30 partial-synthetic motor oil, and the other used an SAE 10W-30 all-mineral motor oil. These oils were of similar chemistry. The test has demonstrated that the low viscosity, SAE 0W-30 oil offered comparable performance to the SAE 10W-30 oil, in terms of engine wear and cleanliness. Excellent connecting rod and main bearing wear, and valve train wear protection was observed for both oils, even though their viscometric properties at high temperatures and under high shear rate conditions are less than the minimum proposed by some engine manufacturers and researchers.
1982-02-01
Technical Paper
821073
Keizo Suzuki, Akihiro Honda, Shizuo Sumi, Mitsugu Kibune
Recently, high pressure injection systems have been widely adopted to reduce black smoke, exhaust gas emission and fuel consumption and accordingly, many troubles have arisen on an engine or a vehicle. One of them is ‘surging problem’ on a vehicle at lower speed and load ranges. This surging problem has strong correlations with ‘abnormal fuel delivery characteristics’. The purpose of this paper is to make clear the cause of these abnormal characteristics and to find out the means to avoid them.
1982-02-01
Technical Paper
821076
Manher D. Naik
A new integrated circuit transducer has been developed for engine oil pressure control in off-road and heavy duty vehicles. The design and development was directed at optimizing cost vs. performance trade-offs. Both, system and component level considerations have been incorporated to achieve the objective. Total error of less than 2% of full scale has been accomplished with possible further improvement using system options. Of particular interest is the structural design that meets environmental reliability and which can be extended for pressure control applications in pneumatic and hydraulic systems in off-road and heavy duty vehicles.
1982-02-01
Technical Paper
821077
Gilbert W. Pilz
Items to consider when specifying, installing, or troubleshooting new hydraulic systems involving flow, temperature, or pressure sensors. Also covered are hydraulic noise and sensor location, the reduction of induced errors, electrical noise and wiring, and the installation of indicators.
1982-02-01
Technical Paper
821056
Jack L. Johnson, Gary D. Kane, Jay A. Sorenson
A proportional electrohydraulic control valve is an ideal interface between the electronic “brains” of today’s powerful microprocessors and other super chips and the muscle of the hydraulic system. In many machines, hardware constraints result in controls which are difficult for a human operator to manage and require considerable experience and skill to become proficient. The microprocessor can be used to convert the familiar X-, Y- and Z axis thinking of an operator into the complex motions of the basic machine and thus produce a machine which is at the same time easy to use and predictable with minimal experience. The purpose of this paper is to relate the authors’ experiences in building a three axis machine actuated by a computer controlled, proportional electrohydraulic valve. It deals with the basic machine, the hydraulic system, the electronic system and the software.
1982-02-01
Technical Paper
821055
Henry A. Schmidt
The present trend in control systems is to extend the application possibilities of existing fluid power technology by using the intelligence, flexibility and speed that the micro-computers are offering in a constantly improving cost efficient manner. Several years ago it was pointed out that the micro-computer’s role in closed loop control would involve the following areas: -Closing the loop - Pre-loop processing - Peripheral processing - Adaptive control - “Smart” redundancy - Improved time-optional control By example, this paper* will show how the first three of the six above areas were involved in Extending Servo Applications.
1982-02-01
Technical Paper
821054
Ken Kolegraff, Steve Lang
Well defined design criteria and extensive testing are necessary to develop a reliable agricultural vehicle monitoring and information system.
1982-02-01
Technical Paper
821058
N. A. Richardson, R. L. Lanning, K. A. Kopp, E. J. Carnegie
This paper considers alternative methods for measuring the true ground speed of tractor vehicles as a means for controlling wheel slip to improve traction efficiency and reduce vehicle and tire wear. Test data are presented on the slip of both driven and undriven wheels for a tractor operating under various speed, load, and soil conditions. Data from a “fifth wheel” operating on smoothed and compacted soil behind a draft sled also is included. Vehicle speed determined from the speed of undriven wheels as well as vehicle speed derived from driven (slipping) wheels using a number of data processing strategies is not sufficiently accurate for either vehicle monitoring or closed loop control. The errors of single and dual beam doppler radar speed sensors caused by vehicle motion are analyzed. Single beam radar systems are shown to operate with an accuracy acceptable for operator control using signal integration times greater than approximately one second.
1982-02-01
Technical Paper
821057
Kazuo Uehara, Hiroyoshi Tominaga
Hydraulic excavators can work on both powerful and fine jobs, which are executed safely. In conventional hydraulic systems of excavators, exhausted hydraulic energy losses were generated with fine control for attachments or with force limit. Recently, variable displacement axial piston pumps equipped with energy saving controls have been developed and made available for hydraulic excavators. With such energy saving controls which decrease mean fuel consumption of excavators, attachment drifts and noise are diminished, engine start during cold weather is made smoother and life of working fluid may be elongated.
1982-02-01
Technical Paper
821410
J. G. Oliver, M. R. Hoagland, G. J. Terhune
ALPA takes the position that automation of flight-critical systems is acceptable only when the pilot is provided with sufficient information to evaluate the product of the automated process and has the ability to assume manual control of that process. Automatic landing systems are cited as an example of automation without adequate information.
1982-02-01
Technical Paper
821428
J. Hopson, W. Zachary
This paper describes research aimed at structuring decision augmentation system design by defining, developing, and applying appropriate design techniques for a variety of airborne platforms. The goal of this research is to improve combined man/machine system performance by enhancing the integration of information in the total avionics system. Results from several studies are summarized and related to the systematic design/evaluation approach being advocated. The approach described includes: (1) identifying key decision situations and matching them to available decision augmentation techniques; (2) extracting, organizing, and summarizing experienced operator opinion about problems in unaided information processing tasks; (3) estimating effectiveness of candidate augmentation algorithms through the use of operator models; and (4) estimating the cost of candidate augmentation systems. The methods are discussed using examples from airborne anti-submarine-warfare.
1982-02-01
Technical Paper
821514
J. G. Oliver, M. R. Hoagiand, G. J. Terhune
ALPA contends that for Category III the pilot must be provided with an advanced flight situation display which contains position, vector and energy status information. This paper expands on the particulars that such a display should contain.
1982-02-01
Technical Paper
821475
Andrew A. Kozak, Walter D. Brockett, Jeffrey E. Haas
The results of an experimental investigation are presented which establish the effects of surface finish, fillet radius, inlet boundary layer thickness, and free-stream inlet turbulence level on the aerodynamic performance of a small axial flow turbine stator. The principal objective was to help understand why large turbine efficiency is not maintained when a large turbine is scaled to a smaller size and to provide the turbine designer with the performance compromises expected for a small scale design. A comprehensive test matrix was used to gain an understanding of the effects of each variable over the full range of all the other variables.
1982-02-01
Technical Paper
821512
D. L. Perkins, J. H. van der Velden
Flexure testing is used as a qualification test method for hydraulic tube fittings and as a development tool to evaluate the flexure fatigue performance of tube connections. The background of this test is described, and examples of test data for various tube to fitting connections and tube materials presented. The standardization status of this test method is discussed and suggestions for further standardization efforts added.
1982-02-01
Technical Paper
820507
G. P. Balfour
The emergence of high speed diesel engines for cars has emphasized the problems of mounting fuel injection pumps onto engines. Some engine manufacturers are using sheet steel pressings or thin cast brackets which allow the pump to vibrate in resonance in the engine firing frequency range. This increases the likelihood of failure of these brackets in service due to metal fatigue. A theoretical analysis of a simple bracket enables the essentials of the problem to be understood and it allows possible design solutions to be evaluated. This theoretical analysis is complemented by experimental evidence from actual brackets.
1982-02-01
Technical Paper
820443
Andreas Mayer, Gerhard M. Schruf, Hubert Kirchhofer
From a comparison of different methods of supercharging it becomes evident that the pressure-wave-supercharger is a highly efficient device of improving fuel economy of automobiles without loss of performance. Tests on a chassis-dynamometer and computer simulations show that it is possible to save up to 25 % of fuel and at the same time to reduce the emissions of exhaust gases considerably by “Down-Sizing” and “Down-Speeding”.
1982-02-01
Technical Paper
820442
Ryoichi Matsumura, Kazuhiro Higashiyama, Kazuo Kojima
Nissan’s new 2.8 liter in-line 6-cylinder turbocharged engine was developed for Che Datsun 280ZX in order to achieve higher performance and improved fuel economy. The Electronic Concentrated Engine Control System (ECCS), controlled by microprocessor, is provided for this 2.8 liter turbocharged engine. ECCS controls fuel injection, ignition timing, EGR rate and idling speed. It solved the problems related to power and fuel economy by optimizing the control parameters. Further, this system contains a barometric pressure compensator and a detonation controller; thus, the performance of this engine is efficient over a wide range of circumstances and fuel octane ratings. During the development of the engine, computer simulation was employed to predict engine performance and select turbocharger size, valve timing and other important factors.
1982-02-01
Technical Paper
820441
W. Brandstetter, R. Dziggel
Volkswagen produces a series of 4-, 5- and 6-cylinder naturally aspirated Diesel engines of the swirlchamber type since 1978. On this basis the development of a 4- and 5-cylinder turbocharged engine was begun. The paper describes the design and development highlights of the 4-cylinder engine with a nominal power of 51 kW and the 5-cylinder version with 64 kW power output. The performance characteristic of the major engine components as well as exhaust emissions and fuel consumption, measured on the engine dynamometer and in actual vehicle installation, are reported.
1982-02-01
Technical Paper
820459
Shinsei Maruyama
It is usually not easy to know the gear ratio of automatic transmission with planetary gears. The author developed an easy way to calculate the gear ratio by using a simple relative speed diagram. With this method, as even a graduate of junior high school can calculate the gear ratio of relatively complicated automatic transmission, the method is widely used at vocational centers, vocational schools and junior colleges of vocational training dotted all over Japan effectively.
1982-02-01
Technical Paper
820762
S. Wahid Zewari, Bayard E. Quinn
A comprehensive survey of literature in the field of vehicle dynamics reveals an enormous amount of individual efforts in promoting the understanding of this field. One of the most talked about classical models is the so-called “bicycle model”. Other similar models exist, but while producing preliminary and ready estimates they exclude important features such as roll and pitch degrees of freedom and dynamic load transfers. The next generation of models seems to be so complex that a mere review of them requires exhaustive endeavors. One has to devote considerable time and effort to work with such models, not to mention the need for and access to big corporate computing facilities. The main purpose of this paper is to establish a mathematical model of minimum complexity without loss of generality. It will enable one to study the dynamic behavior of cars in executing maneuvers and undergoing severe braking.
1982-02-01
Technical Paper
820761
Ken Kamijo, Harutoshi Tsujimura, Hideo Obara, Masaaki Katsumata
In our study we have attempted to determine a method for objectively evaluating seating comfort. Forty-three different front passenger car seats were subjectively evaluated for comfort under static conditions. The following objective data for these seats were measured for possible correlation with the subjective evaluation: static pressure distribution characteristics, static load/deflection characteristics and vibration characteristics. The pattern of the static pressure distribution was found to approximately correlate with the difference between comfortable and uncomfortable seats. It was also found that the sensation of being cushioned, one of the subjective evaluation factors, was related to the natural frequency obtained from the vibration experiments as well as to the static spring constant obtained from the static load/deflection experiments.
1982-02-01
Technical Paper
821030
Carmine Luciani
Military vehicles operating in northern climates require heating equipments to assist engine starting and for crew compartments. Current fuel-burning heaters obtain their electrical power from the vehicle’s batteries, hence, the batteries’ energy is reduced at the time the starting requirements are the greatest. A thermoelectric heater system has been studied whereby heat is transferred into the coolant and electrical power required for the heater’s operation is self generated. Included in this power is sufficient electric current to trickle charge the vehicle’s batteries. A design and experimental data are described.
1982-02-01
Technical Paper
820992
Allen L. Osborne, Douglas E. Johnson
Addition of a turbocharger to a modified production passenger car engine increased power output enough to set a new class record at the Bonneville Salt Flats. Speed achieved in the “D/GT” class was 303 km/h (188.394 mile/h) Power developed by the 2.8L (170 in3) engine was 277 kW (372 hp estimated) at 6000 r/min. Changes to the production engine were: reduced compression ratio (6.3:1), installation of a modified camshaft, installation of a fabricated exhaust manifold and intercooler, installation of the turbocharger, and fuel system modifications to increase fuel flow.
1982-02-01
Technical Paper
821027
Malay K. Kar
The variations of torque in drivelines with single and double cardan U-joints in a 4-wheel-drive articulated farm machine in motion have been studied by computer simulation. A mass elastic model for an engine, power train and the machine is used for the simulation. The effects of tire slips and traction parameters on torque variation of drive shafts have also been included in the study. The torque in drive train input drive shaft with single U-joints having large angular unequality for 40 deg. articulation and 15 deg. oscillation about center pivot has shown severe fluctuations with reversals. The yoke accelerations are also beyond acceptable values. The power train output shaft does not show much of a torque variation because of lower speed and effective inertias and stiffnesses. The driveline torque variation is reduced when the angular unequality is made smaller.
1982-02-01
Technical Paper
821026
William D. Smith, Daniel P. Kauper
Reduction of laboratory test data into report ready form can often be an overwhelming task in spite of the advent of modern computers. Analysis of transient type test data is most useful if accomplished at the test cell where decisions can be made and testing can continue. A processing digital oscilloscope can capture data similar to the conventional oscillograph recorder, but with the added luxury of reducing the data to whatever form is desired and producing either or both a printout or X-Y plot of the results. The processing digital oscilloscope can be as portable and as easy to set up as the oscillograph, making it a valuable R & D laboratory tool.
1982-02-01
Technical Paper
821048
Edward C. Chiang, Vincent J. Ursini, John H. Johnson
A computer simulation program was developed to simulate the thermal responses of an on-highway, heavy duty diesel powered truck in transient operation for evaluation of cooling system performance. Mathematical models of the engine, heat exchangers, lubricating oil system, thermal control sensors (thermostat and shutterstat), auxiliary components, and the cab were formulated and calibrated to laboratory experimental data. The component models were assembled into the vehicle engine cooling system model and used to predict air-to-boil temperatures. The model has the capability to predict real time coolant, oil and cab temperatures using vehicle simulation input data over various routes.
1982-02-01
Technical Paper
821047
Richard C. Perlberg, James H. Cooper
The usage of self-lubricated and pre-lubricated bearings is growing in many industries. The necessary parameters for specific application of these bearing types will be examined and how each effects the bearing operating life. A method will be presented that will enable the design engineer to choose a bearing material and subsequently prescribe lubricating intervals and wear life. A review of maintenance procedures will also be outlined in comparison to conventional type bearings with primary concentration on pinned joints and other highly loaded joints.
1982-02-01
Technical Paper
821046
Chris Robinson
The calculation of rolling element loads and fatigue life for a roller bearing usually assumes that the raceways are cylindrical and rigid. That is, the rolling element loads do not distort the raceways. In some cases, this is a poor assumption and results in improper bearing selection and unsatisfactory performance. This paper describes an analytical method to determine the influence of race deflections on bearing performance. The example of a bearing mounted in a gear bore is used to illustrate how these deflections can result in significant changes in bearing performance.
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