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Viewing 164461 to 164490 of 185592
1969-02-01
Technical Paper
690401
Robert A. Nelson
1969-02-01
Technical Paper
690404
E. H. Warne, R. W. Rigby
The increasing requirements of the modern advanced technology engine have involved a reappraisal of control philosophy to achieve the optimum form of control to suit a specific application, taking into account the need to produce the best engine performance, and at the same time maintain the highest reliability. Control system requirements have been considered and a system evolved which is described for the Rolls Royce RB.211 engine. The philosophies underlying this choice are presented and the hybrid electrical control system is discussed in detail.
1969-02-01
Technical Paper
690405
Robert J. Bussolari
The JT9D turbofan engine, soon to be in airline service on the next generation of advanced jet aircraft, will incorporate the Hamilton Standard JFC 68 main fuel control and EVC 3 engine vane control. Now in production, this control system embodies advanced control technology while retaining the basic advantages of present operational systems. Its specific advantages are improvements in weight, performance, reliability, and durability over present commercial jet engine control systems. This paper presents a discussion of the design philosophy used in creating the system, a description of the system and some advanced techniques used in its development.
1969-02-01
Technical Paper
690408
J. M. Naish, M. F. von Wieser
Effects which normally diminish the value of a manually flown instrument approach are examined in the light of flight test results with the Head-Up Display (HUD). It is possible to avoid shortsightedness (space myopia) and disorientation phenomena associated with poor external visibility, by choice of display position and format, allowing an efficient alternation between display and forward view. The display can also be designed to fit the man, in both static and dynamic characteristics, with benefits of rapid learning and accurate tracking. These results remove the basis for supposing man's intervention in the all-weather landing to be disastrous. On the other hand, man's participation may be necessary, because more information is connected with a safe approach than can be dealt with by an unaided machine. Synthesis of an automatic system with HUD may turn out to be the most acceptable solution to the overall problem of all-weather operation.
1969-02-01
Technical Paper
690410
M. J. Green
Rolls Royce has been developing thrust reversers and noise suppressors since 1956 and over the years has produced units for a variety of civil and military aircraft. This paper describes the various models and specifies the essential requirements that ensure comparability and reliability among major applications.
1969-02-01
Technical Paper
690409
STUART K. WOOD
1969-02-01
Technical Paper
690522
Joseph D. Walter, George L. Hall
Two improved versions of a recently developed miniature force transducer were used to measure cord loads at the crown, shoulder, and sidewall of bias and belted-bias automobile tires under different testing conditions. As a transducer at a given location passes through the footprint, a “basic shape” for the cord force pattern is generated for straight ahead rolling and cornering. Factors such as wheel load, inflation pressure, obstacle impact, tire speed, rim width, and frictional properties of the tire-drum interface can affect the total force excursion and/or the base line value but do not affect the basic shape of the patterns. For both bias and belted-bias constructions significant ply-to-ply cord force variations were detected, and the cord force pattern observed in the first ply as the transducer passes through the footprint is nearly a mirror image of that in the second ply at the same location.
1969-02-01
Technical Paper
690519
Ather A. Quader, Phillip S. Myers, Otto A. Uyehara
Monochromatic ultraviolet (UV) absorbance, temperature, and pressure histories of unburned gas in a single cylinder CFR engine under motored, fired, and autoignition conditions were recorded on a multichannel magnetic tape recorder. Isooctane, cyclohexane, ethane, n-hexane, n-heptane, 75 octane number (ON), 50 ON, and 25 ON blends of primary reference fuels (PRF) were studied. Under knocking or autoignition conditions a critical absorbance at 2600 A was found, whose magnitude was independent of engine operating variables and dependent only on the knock resistance of the fuel. This absorbance increased rapidly when a certain temperature level was exceeded during the exothermic preflame reactions.
1969-02-01
Technical Paper
690520
John H. Varterasian
Annoying “whines” or discrete tonal noises often result from the normal operation of rotating equipment due to the even spacing of the basic load carrying elements. This applies to gear teeth, impeller blades, machine tool cutting blades, and snow tire treads, for instance. Whenever it is possible to unevenly space the elements, the “whines” can be effectively reduced. This paper uses snow tire tread noise to demonstrate a mathematical way for computing an uneven spacing so that the excitation or noise source is in the preferred form for whine reduction -- “white noise.” White noise is analogous to white light which is comprised of many colors, each color having a different frequency. Thus, a mechanical design is computed using a criterion described in the frequency domain. The method uses the mathematics associated with classical “frequency modulation” theory and, therefore, is called “Mechanical Frequency Modulation” or MFM.
1969-02-01
Technical Paper
690518
David K. Trumpy, O. A. Uyehara, P. S. Myers
This paper tells how a model describing the chemical reactions occurring in the fuel-air mixture prior to the arrival of flame in an engine was constructed and the energy equation, including the rates of reaction as predicted by this model, integrated over the fuel-air mixture history. The kinetic model predicted sudden oxidation of the fuel in times of the order of magnitude of knock experimentally observed using ethane in a CFR engine.
1969-02-01
Technical Paper
690515
Michael H. Collins
This paper discusses in detail a new technique for air-fuel mixture entering individual cylinders of a multicylinder engine. The method described provides estimates of the weights of both air and fuel entering individual cylinders and the proportions of the fuel that are present as liquid at points just upstream of the inlet valves. The technique has been developed for steady-speed conditions and is not applicable to transient operating conditions.
1969-02-01
Technical Paper
690516
T. J. Sheahan, C. J. Dorer, C. O. Miller
Multifunctional gasoline additives in use today fall in two general categories, the conventional type and the newer detergent-dispersant additives. The value of the detergent-dispersant lies in its ability not only to keep the carburetor clean but also to minimize the buildup of hard refractory deposits on automotive intake valves and to supplement the cleaning power of the engine oil. Engine tests confirm the effect of the detergent-dispersant. Cleanliness is enhanced in standard tests designed to measure lubricant performance under low and medium temperature engine operation. Intake valve deposits are modified in laboratory and field tests. Bench scale tests show that when the detergent-dispersant is properly formulated, treated fuels may be satisfactorily handled by refiners in storage and distribution systems.
1969-02-01
Technical Paper
690530
A. G. Imgram, Donald K. Miner
At the 1965 SAE Mid-Year Meeting in Chicago, fleet operators commented on hydraulic brake tube failures. Since little factual information was available on the effects of service life on the performance of hydraulic brake lines, a program was initiated to obtain this information. Results of the program indicate that corrosive deterioration of the steel hydraulic brake tubing now being used on cars and trucks creates maintenance problems and can be a safety hazard. The investigation also showed that the performance of presently used brake tubing becomes highly erratic after four to six years in service. Age of the vehicle appears to be more significant than mileage relative to brake tube corrosion. However, there are so many variables which influence brake line corrosion that attempts to correlate the results of the investigation with any one factor, such as age, are difficult.
1969-02-01
Technical Paper
690527
Tadashi Okada, Takeo Sagishima
Theoretical calculation and experiments are made to make clear the transient response of a front wheel drive vehicle to change in tractive force. If the tractive force acting on the front wheel is reduced suddenly from a large stationary value, the turning radius decreases rapidly, and the stability and controllability of the vehicle decreases. The following means are effective to improve stability and controllability: establish relations ∂C1/∂D1 > 0 and ∂T/∂D1 < 0; make the value of C1 + C2 as large as possible; maintain a relation C1 < C2; and increase rigidities of shafts and links of steering system, where C1, C2, T, and D1 are the cornering coefficient of the front wheel, that of the rear wheel, the aligning torque of the front wheel, and the tractive force at the front wheel, respectively.
1969-02-01
Technical Paper
690570
Saul Herscovici
A simple and economical testing fixture and method that may be used for determining the static and dynamic coefficients of friction and the operating conditions that cause their variation is described in this paper. Its advantages are compared to those of a partial vehicle test fixture. This testing method could provide a basic set of data that can be properly converted by the designer to predict the response of a clutch or brake in a new application.
1969-02-01
Technical Paper
690572
Lubomyr O. Hewko
This paper discusses the principle of operation and dynamometer test results of a fixed ratio, planetary speed reducer which uses preloaded, lubricated rollers for transmittal of power. The unit features a torque actuated, automatic preloading mechanism which prevents roller slippage even under severe overload and greatly improves reliability, life, and efficiency of the drive. Test results indicate efficient, quiet, and vibration free operation at pitch line velocities up to 30,000 fpm, such as might be encountered in turbomachinery. Examples of roller traction drives ranging from 500 to 3 hp tested in several applications are also briefly discussed.
1969-02-01
Technical Paper
690566
Lyle S. Martin
The digital computer has greatly enhanced the ability to analyze accurately the performance of hydrostatic and hydromechanical transmissions. The requirements for developing a computer program for analyzing the transmission's performance were to: 1. Describe the transmission's performance data in a manner readily usable by the digital computer. 2. Obtain accurate data from the hydraulic components. 3. Prepare a program which is capable of analyzing the transmission's performance at any combination of operating conditions throughout the operating spectrum of the transmission. 4. Present the output data in a form readily usable by design and application engineers. This paper describes how the above program was developed for analyzing both the transmission's performance and performance of vehicles using the transmission.
1969-02-01
Technical Paper
690565
Michael J. Pannucci, Ghassan S. Tayeh
Abstract This paper discusses a computer-aided bearing design and manufacturing system believed to be unique in the bearing industry. The system is used primarily to design bearings to meet specific applications and to predict the performance characteristics of bearings under conditions of stress, deflection, torque, etc. Advantages realized from the system include better customer service, reduction in the amount of routine design work, and a reduction in the overall cost of the bearings.
1969-02-01
Technical Paper
690567
Garth O. Hall
The ride comfort problem is reviewed. Some of the solutions to the problem are discussed together with evaluation methods which insure proper matching of the dynamic characteristics of seat suspensions to the vehicle.
1969-02-01
Technical Paper
690578
Charles E. Horne
Prior to the late 1940's, there were not many application of needle bearings in farm tractor drivelines. However, when more expanded performance was demanded of farm tractors, modern technology necessitated a new look at their use. This paper discusses the newer applications of needle bearings, dealing with the most basic types and uses. Requirements are listed and speeds and loads to which they are exposed are summarized.
1969-02-01
Technical Paper
690577
H. R. Neifert, F. J. Wren
This paper discusses how periodic revision of tapered roller bearing ratings and reappraisal of the rating formula used by The Timken Roller Bearing Co. are accomplished by a continuing testing program on standard product bearings. An extensive sampling plan, designed to include bearing product up to 6 in. O.D. from both domestic and overseas manufacturing plants, is fully described. A review of recent fatigue tests on over 5000 bearings illustrates the experimental basis for the rating increases announced in 1967. Limited bearing fatigue tests conducted under conditions of lubricant, temperature, and speed different from those used for establishing bearing ratings indicate the need for determining rating adjustment factors to compensate for the influence of the application environment.
1969-02-01
Technical Paper
690580
John Bell
Abstract Discussion in this paper is centered on general problems of subarctic operation, results of the 1968-1969 winter testing at Ft. Churchill, Manitoba, Canada, and the testing planned for the 1969-1970 season at Ft. Churchill. Significant findings from the 1968-969 testing indicate the vital importance of care in preparation of vehicles for the arctic, the need for greater simplicity and reliability in design of winterization systems, and the inadequacy of currently used elastomeric components (hoses, o-rings, etc.).
1969-02-01
Technical Paper
690574
Herbert A. Jespersen
This paper describes in detail the design of a new concept of an all terrain vehicle. It is new because of its small size, completely flexible rubber tracks, and twin, manually controlled hydrostatic transmissions for fully modulated control of the vehicle. Many configurations for this type of vehicle are outlined and the reasons for selecting the final design are given.
1969-02-01
Technical Paper
690573
Ross V. Eskelson
Many vehicles today use the title All Terrain Vehicle although none of them have true all terrain capabilities. To provide the performance capabilities required and the dependability needed, designers still find it necessary to design for the specific use intended instead of being able to design a universally accepted vehicle for many purposes. The introduction of recently available hydrostatic components and suspension components which eliminate the need for lubrication should extend the versatility and dependability of off-highway vehicles.
1969-02-01
Technical Paper
690576
Charles W. Williams, Joseph S. Learman
Accelerated life tests of roller bearings manufactured by conventional means and by forging from bar and plate are described; test results made by Weibull plot are also presented. Grain flows of races manufactured by the various processes are illustrated and described.
1969-02-01
Technical Paper
690575
L. R. McGrath
Scientific and technological advances with an assist from the population increase have been instrumental in the creation of more available time for leisure and enjoyment. The design of the Terra-Tiger, a six-wheeled, lightweight, highly maneuverable sports type vehicle was intended to fill a market which would help satisfy the needs of leisure time. The text of this paper describes the vehicle, its operation, and its engineering features.
1969-02-01
Technical Paper
690555
Ralph W. Holmes
This paper describes the application of hyifraulically powered wheels to a logging trailer which is pulled by a 225-HP tractor. It discusses the advantages of the hydrostatic transmission as a means empowering the trailer. The hydraulic circuitry and its operation is examined. A cutaway view of the wheel is used to explain the operating features. Performance figures are displayed and component arrangement on the tractor are shown. Other applications of the same hydraulic wheel are presented.
1969-02-01
Technical Paper
690554
John Kurelek, John J. Denovan
Koehring-Waterous has developed a stump area pulpwood harvesting machine which promises to make a major reduction in the labor content and cost of pulpwood. This one operator machine fells, limbs, tops, bucks, forwards, and truck loads its seven cord load of 8 ft pulpwood in less than 2 hr. Some keys to its successful operation are: a large, articulated, rubber tired vehicle; a vertical, automatic tree processing tower; a unique log handling and storage method; extensive use of oil hydraulics; and design for reliability in woods.
1969-02-01
Technical Paper
690556
J. L. Frank, D. E. Bowman
This paper describes a simulation of a mobile equipment closed loop hydraulic position control system, performed on a digital computer using a modeling program. Features are cylinder nonsymmetry, bulk modulus varying as a function of pressure and entrained air, valve pressure/flow, and pump pressure/flow characteristics. Results indicate that the most critical parameters, based on effect on performance and difficulty in predicting their values, are damping and bulk modulus. The simulation can be readily extended to include other effects such as cylinder and load stiction and Coulomb friction, time varying externally applied loads, and valve underlap or overlap.
1969-02-01
Technical Paper
690550
W. P. Panny, Arnold K. Riddle
Two configurations of highway truck-trailer combinations being evaluated for hauling gcw loads over 100,000 lb are triples (27 ft trailers) and long doubles (40 or 45 ft trailers). If and when these units become legal, the triples will probably be more widely used because of their better maneuverability which would make it feasible to operate both on and off the thruways. It is generally agreed that two driving axles would be required for the higher gcw loads in order to provide the needed gradeability and give acceptable axle component life and tire mileage. In the case of triples, the 4 × 4 tractor is the ideal power unit. Tests have shown that on snow-covered grades, the 4 × 4 has superior traction characteristics over the tandem 6 × 4 tractor having the same fifth wheel loading. The axles for a 4 × 4 power train should provide for a 2 to 1 proportioning of the torque between the rear and front axles for equal tire tractive effort.

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