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Viewing 15061 to 15090 of 19775
1984-02-01
Technical Paper
840440
G. R. Edgar, D. A. Gore
Abstract RCA has developed a unique technique for the early detection and identification of rolling element bearing failures within gearboxes. This unique technique is not dependent upon any previous measurement taken on the gearbox under test and does not require the collection of data over a lengthy time period for trend analysis. A hand-held analyzer has been constructed that successfully detects minor spalling damage in the ball and roller bearings in a variety of gearboxes.
1984-02-01
Technical Paper
840453
Antonio Formia, Franco Villani, Fernando Negro
Turbocharged engines are more exacting than naturally aspirated engines both as regards lubricating oils and engine main components - particularly crankshaft and rod bearings - since they have to cope with the increased loads arising from higher combustion pressures. These problems can be partly solved by improved oil filtration in the lubrication circuit. An effective solution is the so called double filtration. The double filtration filter, described in this paper, is composed of two sections housed in one standard easy-change cartridge. Each section has a specific function: fine filtration in the by-pass section and coarse filtration in the full-flow section. Structure of filter, filtration characteristics and engine test results are described here. Further possible developments are also mentioned.
1984-02-01
Technical Paper
840098
G.S.A. Shawki, M.O.A. Mokhtar, M. Rafaat
This paper presents a simultaneous solution of both Reynolds equation for hydrodynamic lubrication and Laplace's equation for a porous matrix, the continuity of pressure at film-bearing interface being maintained. Performance characteristics for an infinitely long bearing are obtained and design charts comprising optimum curves for maximum load capacity, minimum friction loss and maximum utilization of bearing bush porous material are displayed.
1984-02-01
Technical Paper
840097
M.O.A. Mokhtar, M. Rafaat, G.S.A Shawki
Results of experiments conducted on complete as well as partial porous journal bearings operating under steady conditions are herein presented. Performance characteristics presently determined include eccentricity ratio, coefficient of friction and attitude angle. Values of the permeability parameter ranged in experiments between 2.54×10−3and 4.35×10−2. Test results show quite good agreement with theoretical predictions of the authors. Comparison between results obtained for partial bearings, also for complete bearings with holes intensionally drilled in the region of supposedly negative pressure implies the validity of discarding the negative pressure zone as postulated by the authors in their proposed theory.
1984-02-01
Standard
AGS2067-6
No scope available.
1984-02-01
Technical Paper
840224
Brian O'Neill
Since the 1973 model year minimum levels of new car bumper performance have been specified by federal standards. Beginning with the 1974 model year, the safety bumper standard required that bumpers protect safety related equipment in 5 mph front-and rear-into-barrier tests. This standard was superceded in the 1979 model year by the no-damage standard which restricted dollar damage in the same tests. For 1983 and later models the barrier test speed requirements of the no-damage standard were reduced to 2.5 mph. There is convincing evidence from crash tests and insurance data from real world crashes that the federal 5 mph bumper standards substantially reduced much of the unnecessary damage that was occurring in low speed crashes because the performance of pre-standard bumpers was so poor. There is a real danger that this progress will be eroded, however, due to the weakening of the no-damage standard.
1984-02-01
Technical Paper
840405
J. L. Rees
A description of the sponge-dense rubber body seal is presented, along with its development and advantages in vehicle manufacture. The components of a body seal and retainer as they affect its performance are discussed in detail. Also described are the various types of rubber materials used in seals and weatherstrips; special requirements to satisfy service conditions; and procedures for testing vehicle sealing products.
1984-02-01
Technical Paper
840404
Robert A. Brullo, Allen M. Sohlo
Rapid changes in part requirements, due to the emphasis in recent years placed upon overall energy conservation, environmental quality, and safety, have greatly increased the demand for high performance materials. Many of the changes in component designs are exceeding the capabilities of conventional elastomers. Fluoroelastomers are no longer considered the material of last resort and are becoming an integral part of initial application development programs. This paper will review three specific applications of growing importance in solving critical engine and drivetrain seal problems.
1984-02-01
Technical Paper
840408
S. R. Foster, D. R. Capriotti
Continuing regulatory and consumer pressures and energy considerations have forced significant changes in the automotive industry. The resulting vehicle design objectives, which include downsizing, the move to front wheel drive, trends in optional equipment and fast-paced competitive design all have affected the amounts and types of elastomers used on today's vehicle. This paper will discuss some of the changes in elastomer usage, review some of the technical reasons for these changes and suggest trends for automotive elastomers in the next several years.
1984-02-01
Technical Paper
840411
Ismat A. Abu-Isa
The effects of methanol/gasoline mixtures on swell properties and tensile properties of selected automotive elastomers were investigated. Two gasolines with aromatic contents of 30% and 50% were used in the investigation. Equilibrium swell measurements and tensile measurements were conducted using ASTM standard procedures. The results show that although few elastomers were affected drastically by pure gasoline (e.g. natural rubber) and a few by methanol (e.g. fluorocarbon elastomer) most of the elastomers were more severely affected by mixtures of the gasoline and methanol rather than the pure components. Presence of higher aromatic content in the methanol/gasoline mixtures led to additional deterioration of properties. The data on all elastomers except the fluorocarbon can be explained in terms of the solubility parameter concept.
1984-02-01
Technical Paper
840504
Horace Holmes
The paper describes several methods of designing threaded fasteners which will not be affected by vibration, transverse loading or shock. Descriptions and drawings are shown of some of the thousands of successful tests made on these fasteners in the United States and Europe. A few of the most interesting places are noted where these fasteners are currently being used.
1984-02-01
Technical Paper
840573
Kunio Namiki, Kenji Isokawa, Hisayoshi Kojima, Nobuhiko Okoshi
JIS SCM440M (SAE4140H), heat treated to the strength level of 120 to 140 kgf/mm2(171 to 199 ksi) -ISO 12.9 class-, is currently used for cylinder head bolts of Japanese passenger cars. Lower alloy steels, such as SAE 1541 for example, have not been substituted for JIS SCM440H so far because of their high susceptibility to delayed fracture. Daido Steel has tackled this problem and succeeded in applying the lower alloy SAE 1541 steel to 12.9 class cylinder head bolts by enhancing the resistance to delayed fracture by reducing impurities, especially sulphur. In this paper mechanical properties and delayed fracture characteristics of SAE 1541-ULS (Ultra Low Sulphur) steel are reported. 1541-ULS (S<0.005%, S+P< 0.020%) shows outstanding resistance to delayed fracture compared to conventional steel. Furthermore, the amount of MnS inclusions decreases remarkably in ULS steel, which results in high toughness.
1984-02-01
Technical Paper
840189
B.G.J. Williams, M.C. Bannard
There has been and continues to be a growing trend in world engines towards the use of ‘Bi-Metallic’ constructions, ie. engines which feature head and block castings of different materials. The use of aluminium cylinder heads with cast iron cylinder blocks is a typical arrangement. Figure 1 indicates some of the significant differences in the physical properties of cast iron and aluminium. As can be seen, aluminium offers a number of advantages from an engine design viewpoint, notably weight saving and heat transfer efficiency. The use of aluminium can, however, result in a number of potential difficulties in terms of its effect on cylinder head gasket performance. This paper considers these difficulties with particular reference to ‘fluid sealing’.
1984-02-01
Technical Paper
840190
Klaus Lönne, Klaus-Peter Majewski, Brian A. Newman
Extensive measurements taken on a fired engine and in a simulator have shown that there is an additional cylinder distortion superimposed on the initial distortion, which is caused by the clamping of the cylinder head. This additional distortion factor is mainly caused by quasi-static, thermal-conditioned sliding movements between the head, gasket and block. Superimposed cylinder distortion and sliding movement are closely related and are influenced by the friction conditions. A new type of coating for the combustion chamber edgings of cylinder head gaskets will be presented. By the application of this coating, especially in bimetal engines that are prone to relative movement at the block and head, the superimposed distortions are considerably reduced. Additional functional advantages of this sliding coating for the operational reliability of today's generation of engines will be shown.
1984-02-01
Technical Paper
840191
Akira Matsushima, Masamichi Ohtaki, Hiroshi Hirabayashi, Susumu Iida, Hitoshi Chikamori
According to the 1982 Japanese Engine Data Book, 249 automobile engine models are used, including gasoline and diesel engines. Among them, 87 models (approximately 60% of all 4-cycle gasoline engine models), are designed for small passenger car applications, with displacements between 1.51 and 2.00. This paper will highlight the area such as Seals for Automobile Engine Applications, Present Automotive Engine Seal Situation in Japan and Countermeasure Activity for Field Claims.
1984-02-01
Technical Paper
840184
L.A. Horve
Some elastomeric materials used in the manufacture of radial lip seals absorb moisture. This moisture tends to soften the material and cause the hardness, radial load and lip opening pressure to decrease. When exposed to a dry atmosphere, some materials will release the moisture. The radial load, hardness and lip opening pressure will then increase. A study was performed to determine the effect of moisture on seal physical properties, functional life and cold temperature performance. The seals were made from a polyacrylate material. Polyacrylates absorb and release water readily. It was found that variations in environmental conditions did not affect seal function. The physical properties of these seals varied significantly with humidity. Seals made from polyacrylate materials should be preconditioned at a known humidity and temperature level before radial load, lip opening pressure and hardness measurements are made.
1984-02-01
Technical Paper
840185
Brian J. Ward
The use of synthetic lubricants as motor oils or as blends with motor oils, will become a reality in the near future. In anticipation of this and to help predict the future needs of the automotive sealing industry, this paper will present test data listing the effects of synthetic lubricants on elastomeric sealing materials. The lubricants used in the testing were 10W30 motor oil, Diester and Polyalphaolef in synthetic lubricants and also blends of both Diester and Polyalphaolefin with 10W30 motor oil. The materials tested were typical engine sealing materials that would come in contact with the lubricants just mentioned. They are Nitrile, Ethylene Acrylic, Polyacrylate, Silicone and Fluorocarbon. The testing of these materials was done at 121°C (250°F) and 150°C (300°F) for 70 hours as per ASTM D471.
1984-02-01
Technical Paper
840188
Daniel E. Czernik
Abstract The cylinder head gasketing of today's internal combustion engines is highly complex and becoming even more so as the engines are being made lighter while developing higher outputs. Delicate stress distribution balancing between the combustion and liquid sealing components is required. Rigorous testing, both static and dynamic, is required to insure long term, high performance sealing. Specialized test equipment and instrumentation is utilized during this testing. This paper presents some of the techniques used in the design of cylinder head gaskets. It also depicts some of the specific tests that are conducted and test results that are required before the gaskets are released to production.
1984-02-01
Technical Paper
840186
Karl-H. Spies, Hermann Rapp, Dieter Fuchs
The development of radial lip seals for the use in motor vehicle is influenced by the special applications and the demand for highest reliability. Special seals must be developed for each application to meet the permanent increasing requirements. The sealing of the crankshaft is a typical example. The paper shows the required steps of development in Europe relating to the seal material and design.
1984-02-01
Standard
AS90A
No scope available.
1984-02-01
Technical Paper
840035
J. Knoll, C. R. Vilmann, H. J. Schock, R. P. Stumpf
Real time work cell pressures are incorporated into a dynamic analysis of the gas sealing grid in Rotary Combustion Engines. The analysis which utilizes only first principal concepts accounts for apex seal separation from the trochoidal bore, apex seal shifting between the sides of its restraining channel, and apex seal rotation within the restraining channel. The results predict that apex seals do separate from the trochoidal bore and shift between the sides of their channels. The results also show that these two motions are regularly initiated by a seal rotation. The predicted motion of the apex seals compares favorably with experimental results. Frictional losses associated with the sealing grid are also calculated and compare well with measurements obtained in a similar engine. A comparison of frictional losses when using steel and carbon apex seals has also been made as well as friction losses for single and dual side sealing.
1984-01-01
Standard
AMS7280C
This specification has been "SUPERSEDED" by the Aerospace Materials Division, SAE, as of July, 1991.
1984-01-01
Technical Paper
845049
Ulf Essers, Peter Gutzmer, Geert Kuipers
The statically indeterminate supported crankshaft system (with several degrees of redundancy) in multi-cylinder combustion engines moves in the main bearings due to the gas and inertia forces acting on it. The sometimes very rapid changes in movement of the individual main bearing journals lead to impulsive force excitations, which act via the lubrication film on the main bearings, generating vibration in the main bearing lane. In order to clarify these relationships, experiments have been carried out on a gasoline engine, whereby, in addition to combustion chamber pressure, recordings are also made of the movements (journal orbits) of all main bearing journals and of the vibration excitation at the main bearing caps.
1984-01-01
Standard
AMS3500D
This specification covers leather tanned with chromium salts and retanned with vegetable tanning material.
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