Criteria

Text:
Display:

Results

Viewing 169981 to 170010 of 185196
1963-01-01
Technical Paper
630327
Howard R. Roberts, Chester H. McCall
This paper presents a review and commentary on some of the fundamental facets of the life testing area of reliability. Although the emphasis employed is on statistical methods, a strictly mathematical treatment per se is avoided. Rather, an attempt is made to illustrate the fact that the problems of life testing present many complications with respect to statistical inference. It is therefore concluded that caution should be the byword in making extrapolations from a sample of life test data to a more general set of conditions. In this regard, particular emphasis is placed on the appropriate selection of life models. Finally, it is proposed that because of the statistical complications involved in many life testing problems (and other reliability problems as well) the statistician should be a member of the reliability engineering team.
1963-01-01
Technical Paper
630326
J. D. Savage
The need for different oils in different systems of the modern United States tractor has complicated servicing and maintenance by the farmer. In Europe this disadvantage has been somewhat overcome by multiviscosity oils suitable for all-season use and by the wide acceptance of a “universal” oil. Those countries that import tractors from both Europe and the United States encounter conflicting requirements. This paper suggests that if United States manufacturers develop a similar “universal” oil for the newer design tractors and adopt sealed-for-life units in their tractors, such improvements will greatly simplify the farmer's maintenance problems.
1963-01-01
Technical Paper
630324
Keith E. Wood
Studies of the causes of torsional vibration in implement and tractor combinations have produced definite rules for design which have eliminated torsional vibration or reduced it to acceptable proportions. There are cases where the natural torsional frequency of the system must be altered to reduce the effect of a forcing frequency. This paper discusses both types and presents means for selecting a suitable powerline stiffness when natural torsional frequency of the system must be altered. When powerline stiffness change is necessary, stiffness is usually decreased. Means of decreasing powerline stiffness, as well as the problems encountered, are considered.
1963-01-01
Technical Paper
630325
N. P. FLYNN, A. O. PUKKILA
The general quality characteristics and availability of fuels and lubricants in overseas markets are reviewed as they relate to farm, construction, and industrial machinery. The differences between these fuels and lubricants and those made in the U.S. are highlighted, and the reasons for these differences discussed. Note is taken of the problems involved in supplying a multiplicity of lubricants to perform similar tasks. Survey data showing the quality of diesel fuels available in specific overseas areas are included. The authors conclude that lubricants of superior quality and diesel fuels of satisfactory quality are available worldwide. Motor gasoline quality, however, varies widely and in some areas is significantly below U.S. octane number levels.
1963-01-01
Technical Paper
630322
Wayne H. McGlade
Modern off-highway vehicles must perform efficiently and reliably under heavy duty conditions. This requires mechanisms that can move and handle material faster and at lower cost. This means bigger powerplants and high capacity power shifted transmissions. The transmission system is critically important to total vehicle performance, reliability, and cost of operation. This paper reviews the various transmissions available and reports the development and experience of the LeTourneau electric drive design.
1963-01-01
Technical Paper
630323
Paul Mitchell
Shock-sorber is a patented device for absorbing shock, vibration, and noise in universal joint and other drivelines. The construction and limits of operation of the unit are described and illustrated. Application and engineering data covering selected machines is included. Several torsional vibration problems encountered on agricultural machines are described together with the solutions through use of the Shock-sorber assembly.
1963-01-01
Technical Paper
630320
J. B. Black
In a torque converter powershift transmission system, a modulated oil pressure engaged oil cooled clutch is added at the input to the torque converter. Modulated control of the clutch engagement is given to the operator and adequate cooling is provided so that the clutch cannot be destroyed under the most adverse operating conditions. This provides the means to: smooth transmission shifts; reduce the energy input to the transmission clutches; and slip the modulated clutch and reduce horsepower delivered to the transmission, thus providing more horsepower for direct engine powered implements at the operator's option.
1963-01-01
Technical Paper
630318
Warren W. Schwid
Air to oil cooling is compared to water to oil cooling, covering various conditions to be considered in the design of a cooler. The following subjects are discussed: minimum oil temperature possible, oil temperature effect on surface required, comparison of surface required with air or water cooling, system pressures, pressure drop, agitation of oil to increase cooler efficiency, and cleanability of each type. Two simple rules are given for obtaining maximum cooling from available space.
1963-01-01
Technical Paper
630316
Joseph H. Miotke
The history of earthmoving equipment is covered, and the basic motions and operations performed by these machines is explained so that the reader will also understand how they perform. Three general classes of earthmoving machinery are discussed: the power shovel, the scraper, and bulldozers and endloaders. These machines perform the same job in the same basic manner as the shovel.
1963-01-01
Technical Paper
630317
H. D. Huggins, Nelson Jarrett
Selection of a water or air cooling medium for engine systems depends on the availability of the medium, the design of the engine, and the conditions under which the system operates. This article presents a number of cases for both water and air cooled systems, compares their characteristics, and describes the design approach toward each.
1963-01-01
Technical Paper
630344
Allan G. Piersol
This paper is concerned with the use of nonparametric statistical equivalence tests as a tool in vibration data analysis and evaluation. The need for equivalence tests is discussed with reference to classical procedures. The desirability of a nonparametric approach to the problem is then considered. A specific nonparametric test based upon the number of runs that are observed in a collection of measurements is outlined. The procedure is illustrated by two numerical examples representing important data evaluation problems.
1963-01-01
Technical Paper
630345
R. W. Mustain
A primary design consideration for any rocket boosted vehicle is the effect of acoustic and vibrational excitations on the vehicle structure and on delicate airborne equipment. These dynamic forcing functions display magnitudes in agreement with spatial patterns and are variant also with time and mission profile. This paper discusses fundamental techniques for the prediction of principal dynamic forcing functions on missiles and space vehicles. Predictions of rocket exhaust noise, boundary layer turbulance, and structural vibrations are presented, and various prediction techniques are examined and compared. Several methods of acoustic/vibration correlativity are utilized to provide comparative environmental vibration levels. The application of environmental vibration levels to the establishment of laboratory test levels is briefly reviewed.
1963-01-01
Technical Paper
630346
Frank Kozin, John L. Bogdanoff
An introductory presentation is given of those features of random function analysis of practical significance to engineers. Included in the presentations are formal definitions of random functions; relationships of member functions to random functions; second order statistical properties of random functions, including covariance; the mean square calculus of second order random functions; member function properties defined by covariances; stationary random functions; and power spectral densities. Brief comments are offered upon the meaning of solutions of stochastic equations.
1963-01-01
Technical Paper
630347
Fred G. Wagner
A new concept for short haul air transports represents the design of a very compact machine made possible by a jet induced high lift system. This arrangement uses stored energy and inducer pumps for moving suction and blowing air on the wing and the tail surfaces. The new concept leads to economically feasible air transports filling an urgent need of the local service airlines.
1963-01-01
Technical Paper
630340
N. M. F. Vulliamy
Development of the diesel has been primarily in extension of engine life and reduction of internal losses at high speeds, rather than in raising maximum operating speeds. The principal justification for diesel engines is fuel economy and low operation and maintenance costs. This paper reviews development of diesels over the past two decades in Europe. A technical discussion of design factors and combustion systems is presented. The author touches on various innovations possible in industrial diesels of the future.
1963-01-01
Technical Paper
630343
Carl B. Pearlston
In the last decade radio noise technology has evolved into radio interference, then electromagnetic interference, and finally electromagnetic compatibility. This discussion provides information on the efforts of the significant groups in the compatibility field. Various committees, subcommittees, and panels have been formed to coordinate activities and communicate information between the various groups, both government and industry, engaged in activities in the electromagnetic compatibility field.
1963-01-01
Technical Paper
630337
James K. Figenshau
Many remotely controlled manipulative devices have been designed and operated successfully for extended periods in nuclear, industrial, underwater, underseas, high temperature, inert gas, hard vacuum, space, explosive, corrosive, toxic, and other hazardous environments. This paper describes the environmental protection for typical manipulative devices and discusses design parameters, methods of operation, design features, materials of construction, and, where possible, operating experience to date.
1963-01-01
Technical Paper
630336
W. R. Dalenberg, R. D. Williams
The new 706 and 806 farm tractor series are described, including their appearance, operation, and engine specifications. A new clutch facing pad material is used - a sintered material used in high temperature aircraft brakes. The hydraulic system has three subdivisions: the front pump system, the rear pump system, and the independent power take-off.
1963-01-01
Technical Paper
630339
Ewen McEwen
This paper deals with the problems of designing tractors to be sold all over the world while at the same time minimizing the variables in order to obtain the economies of mass production. The physical, psychological, and legal requirements and difficulties are dealt with and a summary of the maze of European road and safety regulations is included as an Appendix. The author concludes that since these regulations are inescapable, it is in the interests of the industry to support every effort at rationalizing the requirements among the different countries.
1963-01-01
Technical Paper
630338
Richard H. Sprince, J. L. DeWeese, G. L MacPherson, R. W. Wirta, John Conley, R. S. Mosher
The evolution of the relationship between man and the machine he selects to perform work, from the standpoint of control, is traced through the various eras of history. This, paper describes the cyclic effect in the man-machine relationship, that is, the integration and lack of integration of the operator in the task loop, from the days of the Stone Age through the Machine Age, the Age of Automation, and up to today. Recognizing the increased performance and sophistication of present-day machines, a discussion is presented of the component and equipment design considerations necessary for integrating man and machine through remote controls.
1963-01-01
Technical Paper
630332
W. I. Hamilton
The various factors which should be considered if optimum engine life and performance are to be achieved are discussed in this paper. These factors include ratings or work capacity of the engine, the particular application of the engine, adjusting power output to suit the application, use of torque converters in conjunction with the engine, torsional vibrations, and flywheel size. Examples are presented for each factor, as are mathematical computations and graphic data.
1963-01-01
Technical Paper
630335
Robert B. Singer, N. A. Shealy, W. L Stevenson
This paper covers the development and marketing experience, from an engineering point of view, of four-wheel-drive agricultural tractors up to the present time. The information pertains to the Minneapolis-Moline-type of four-wheel-drive and discloses new information on application data. Specific information is given on how to optimize a four-wheel-drive for agricultural applications; design duty cycle and how this duty cycle was confirmed by experimental and field testing. Trends in the use of agricultural tractors as affected by the four-wheel-drive introduction are also given.
1963-01-01
Technical Paper
630334
R. H. Scott
Due to heat deterioration, maintenance problems, and other economic factors, industry needed improved tires for off-highway production bottom dumps and scrapers. Tests have shown the dual tire design to be the answer to the heat problem, and giving improved ride, steering and controllability, machine performance and durability, tread life, ease of maintenance, and tire and rim savings. The use of duals should, however, be carefully evaluated for the particular application.
1963-01-01
Technical Paper
630360
Robert A. Pustell
This paper presents a discussion of the component evaluation and design development work performed in developing a 4300 F reentry vehicle nose cap temperature sensor. Material compatabilities, insulation resistance, and atmospheric pressure effects on bare wire calibration data are discussed in some detail. The final design is outlined and the application problems discussed. The probe utilizes: a sintered iridium high temperature sheath (4300 F) and platinum 20% rhodium as the low temperature sheath (3000 F); beryllia as insulation -- hard fired at 4300 F and compacted powder at 3000 F; tungsten versus tungsten 26% rhenium as the thermocouple pair.
1963-01-01
Technical Paper
630361
William C. Kuhlman
Thermoelectric outputs of Re - 6W, Re - 9W, Re - 12W, Re - 15W, Re - 5Ru, Re - 10Ru, Re - 15Ru, Re - 10Rh, Re - 20Rh, Re - 10Pt, Re - 30Ir, Re - 5Mo, Re - 10 Os, Re - 20 Os, Mo - 10W, Mo - 20W, Mo - 10Re and Ir - 20Re versus commercial W - 26Re wire are shown. Re - 12W and Re - 15Ru are believed to be potentially the best of these materials. The performance of BeO, ThO2 and HfO2 as thermocouple insulators is shown. BeO performs well to 4400°F but ThO2 and HfO2 should be used with care above 4100°F and 3900°F, respectively. Ir - 15 Os, Ir - 20 Os and Ir - 10Re are shown to have promise for use as thermocouple sheath materials for temperatures to 4500°F in low pressure air for a limited time.
1963-01-01
Technical Paper
630333
D. A. Clendenen
The increased size and capabilities of earthmoving equipment in recent years has resulted in new tire development to keep pace with the durability demanded by high speeds, heavy loading, and extreme terrain conditions. This paper discusses performance, design, maintenance, and economics of single and dual tires, and reports the results of extensive testing to determine the advantages of each type.
1963-01-01
Technical Paper
630363
George W. Burns
The National Bureau of Standards is developing a reference table for the platinum-6% rhodium versus platinum-30% rhodium thermocouple. Thermocouples from three American manufacturers and one European manufacturer have been tested in the 0–1600 C range. The paper discusses the choice of materials and briefly describes the methods of testing used in this work. The results of the tests are compared with a reference curve used in Europe for the thermocouple.
1963-01-01
Technical Paper
630362
Homer Youngs
This paper examines hydrofoils, their history and their markets, and concludes that a second-gene ration family of American designs is in order. A series of prototypes is described for the earlier members of this family, and historic data are utilized to relate their scheduling and their horse-power. “New” information in this paper includes power versus date trends for hydrofoils, a nomograph relating hydrofoil parameters and costs, and an up-dating of past tabulations of hydrofoils and some of their descriptive measures. It is specifically concluded that attack of the indicated second-generation markets should begin without delay.
1963-01-01
Technical Paper
630356
E. A. Calvelli
Investigation of the corrosion problem associated with microbiological contamination of jet fuel reveals a definite relationship between microorganisms and other contaminants. These contaminants include:saline water, rust, surfactants, and dirt. If we destroy the microorganisms without effectively removing the ingredients which cause both their growth in, and the corrosion of wing tanks, we are only flying on borrowed time. The problem of corrosion will never be completely solved by the elimination of bacteria alone. Only a concentrated effort to keep the total list of ingredients out of the fuel system will suffice.

Filter

  • Range:
    to:
  • Year: