Search Results

This paper describes the development of an automated and computerized used oil analysis system designed to monitor equipment and lubricant condition. The techniques covered are differential infrared analysis, membrane filtration, viscosity determination, and analysis of wear metals. The customized used oil analysis is outlined, and field application and case studies described. The system provides an early warning to forestall potential problems and imminent equipment damage, monitors wear and dirt levels, identifies possible deposits and their nature, pinpoints engine conditions causing oil degradation, and recommends corrective action. It also reduces laboratory analysis and reporting time for more rapid response to equipment operators. It has proved to be a valuable tool for predictive maintenance.

The International System of Units, called SI, is now certain to become our measurement system. It is different from the old metric system in many ways and its proper use is important. It does not involve the sizes of things, or standardization of hardware. International engineering standards present an urgent problem, but a different one, that must not be confused with SI. The costs of changing to metric measurement have been greatly exaggerated and can be minimized by a careful planned approach.

A new urban transit bus design has been developed that demonstrates the latest technological advancements in the automotive engineering world. The three prototypes include many innovative designs for passenger comfort, safety, and aesthetic appeal, among which is a low floor height of 17 in, a special entry ramp for the aged and handicapped, independent suspension for better ride and handling, and improved acceleration, performance, braking, and exhaust emission standards.

Computer application in engineering is reviewed from an historical viewpoint. Since 1965, a trend toward integrating computer programs into a design system has emerged. Such design systems are called “Computer-Aided Design (CAD)” systems. A similar trend in manufacturing is also now emerging. Advanced research and development work in the United States and abroad is directed toward capturing manufacturing logic to develop automated manufacturing systems, known as “Computer-Aided Manufacturing (CAM)” systems. It is projected that engineers of the 1970s will witness development of many CAD and CAM systems. It is also projected that a new trend to integrate CAD and CAM systems will emerge in the 1970s.

The author states the climate in the United States favors large jury awards in lawsuits involving malfunctioning products. He proposes the practice of preventive law to minimize the impact of this adverse climate, and presents 11 suggestions to aid in such practice. Finally, various admonitions are presented regarding inspection, testing, and compilation of evidence.

A short survey of the literature about human tolerance to vibrations and about seat transmissibility is presented. A brief summary of European regulations concerning seat characteristics will include not only vibration absorption requirements but also recommended dimensions and necessary adjustments. Safety rules as issued in some countries, in particular for tractor seats, are also discussed. The practical problem of making a seat in accordance with all these factors at a reasonable cost with durability and easy adaptation to the unskilled user will be discussed as a compromise. Conventional systems and new trends are briefly indicated.

Since vehicle seats interact dynamically with the human body, testing the response characteristics of such seats for proper application is important. Likewise, the methods and techniques used for such evaluations are equally important if meaningful results are to be obtained. This paper discusses two quantitative test procedures applicable primarily to judging the relative performance of several seats with regard to dynamic characteristics. In particular, the equipment and procedures necessary to plot seat transmissibility are discussed and specific example data are shown for two suspension seats and a static cushion seat. Also, equipment and procedures for assessing the relative dynamic response index (DRI) are discussed and example results for a suspension seat and a cushion seat are included.

Complete power train assemblies are durability tested in the laboratory by applying real-time, field-recorded axle loads with an electrohydraulic servo system. Transmission shifting is servo-controlled, permitting testing with power shift and power shift-torque converter type transmissions. The load-control system permits selecting any duty cycle or combination of duty cycles for the laboratory loading. Computer analysis of field and laboratory load data gives a damage rate comparison and component life predictions. A general description of test objectives, equipment, and operation, as well as examples of test results and data comparisons, are given.

A theoretical analysis is presented that predicts significant reductions in exhaust pulse amplitudes and hence exhaust noise levels by varying the shape of the exhaust port in a spark-ignited 2-cycle engine. Verification and correlation with experimental results are also presented.

Commencing with a Canadian Federal Department of Transport contract to study the feasibility of snowmobile silencing, the commercial supply of exhaust systems, and the prototyping of representative machines, a considerable amount of data has been accumulated over the past two years in Winnipeg. From this data certain patterns have emerged which we feel provide a basis for developing a pragmatic approach to the problems of reducing the noise level of snowmobiles.

The sound pressure levels experienced by an individual exposed to noise can be obtained irrespective of the nature of the source or the presence of acoustic barriers by monitoring the sound field within the ear. The apparatus developed for this purpose consists of a miniature microphone located on the base of the concha connected to a lightweight instrument package strapped to the subject. The latter contains a modified cassette tape recorder, power supplies, and an oscillator used to record a calibration signal onto each tape and check the performance of the system. A pressure transformation is applied during analysis of the data to compensate for the frequency response of the components or to generate an equivalent sound field that would exist at the center of the head in the absence of the subject.

The paper describes work of the SAE Small Engine Powered Equipment Subcommittee in the development of a new sound level measurement procedure for small engine powered equipment. Data were gathered in an effort to improve the test site used in the measurement of exterior sound level of small engine powered equipment such as mowers, riding mowers, garden tractors, snowblowers, etc. A procedure was developed with a shorter measurement distance and an artificial test surface. The new procedure provides accurate, repeatable sound level data.

Limited route service experience with a commercial 637 CID conversion of a gasoline engine indicated both its potential and the need for its optimization in order to take advantage of the unique characteristics of liquefied petroleum gas fuels. At the request of the Chicago Transit Authority, an engine-dynamometer study, with emphasis on fuel system-ignition relationships, was conducted at the Phillips Petroleum Co.'s Automotive Laboratories. Dynamometer studies led to substantial improvement in fuel economy without depreciation of engine power. Cylinder head redesign by the engine manufacturer permitted lean mixture operation that reduced exhaust emissions to levels calculated to conform to the 1973 federal standards and 1973-1974 California Air Resources Board requirements for heavy-duty engines.

A large number of vehicles are now running on gaseous fuels. Most are using liquefied petroleum gas (LPG), and some are using natural gas (NG). Published studies have listed the advantages and disadvantages of such conversions, but these have had an unexpected degree of understatement and take a very stringent view of the emission advantage, giving the impression that vehicles using gaseous fuels cannot compete with emission control of the clean gasoline-powered vehicles planned for 1975. This conclusion will probably be proved erroneous when all data are available. As compared to clean 1975 gasoline vehicles, gaseous-fueled vehicles will probably be cheaper to run and more reliable. Disadvantages include limited distribution of gaseous fuels, limited fuel-carrying capacity, some regulatory limitations, and a need for more highly developed hardware. Despite these problems, there is a small but important market where conversion will be very profitable for the owner and the community.

The purpose of this paper is to illustrate the value of shot peening in reducing production costs where high volume is concerned. Its potential as a means of reducing part size via increased fatigue strength can result in saving material to the extent of hundreds of dollars per day. The significance of the distribution of residual stresses within the shot-peened part is discussed, and theories are presented in an attempt to explain some of the startling effects of shot peening. The economics of efficient operation of peening equipment are discussed, and suggestions are given to minimize operational costs.

The conversion from submerged arc welding to electron beam welding (EBW) of transmission components at Clark Equipment Co. is described. The latter system permits the consistent holding of close tolerances and the obtaining of controllable and repeatable metallurgical structures. In addition, control of the weld and distortions is increased, and weld joints are made feasible in otherwise inaccessible locations. A brief history is presented which touches on the selection of transmission products for EBW, choice of EBW equipment, preliminary evaluation, and acceptance of the process by personnel. Then, the application of EBW to production parts is discussed.

The use of the Oklahoma State University Pump Contaminant Sensitivity Test, OSU-F2 Multi-pass Filter Performance Test, and knowledge of hydraulic fluid contamination levels in field tests have proved to be highly effective tools in the development of a reliable hydraulic system for a modern farm tractor. Goals for an improved filter system were: To provide as much filter capacity as economically possible; to increase the filter flow rate; to isolate the pumps from the sources of contaminants. These modifications corrected the problems: Brake friction surfaces which generated less contaminant; a pump with greater contaminant tolerance; an improved filtration system.

In any hydraulic system, we can, without reservation, say that the cleaner the fluid the better. But, since absolute cleanliness is usually unobtainable, it becomes important that we can readily measure and define the degree of cleanliness in a practical way. Two parameters seem important: number of particles and particle size. In examining hydraulic components as to type and usage, two areas of particle size are of special significance, 5 and 15 micrometres (μm). By counting all particles in a fluid sample above 5 μm and also counting all particles above 15 μm, two indexes are given from which a contaminant code* is derived. The thesis of this paper is that this code is useful in predicting the performance of specific components with the fluid.

Methods of assessing the ride comfort afforded to tractor drivers by their vehicles and the ride improvement provided by seat suspension are reviewed in relation to information available on the human tolerance to whole-body vibration. Experience with different methods of measurement is reported and a proposal made for the establishment of an internationally agreed method of ride comfort rating based on standardized undulating surfaces over which vibration of the driver's seat is analyzed, using frequency weighting to represent the differing sensitivity of the body to different vibration frequencies.

A farm tractor protection cab made of thin steel sheet pressings is described. The cab is designed and produced using entirely automotive-type procedures. Curved glasses and a dampening suspension of the glasses are found to be an important means of achieving a low noise level in the cab. Using the pressing technique when producing a steel cab makes it possible to give the various cab details rigidity with a minimum of material. When welded together, these details form a very stiff cab body, which gives the necessary mechanical strength. The curved surfaces, the radii, and the round forms, which from a tooling point of view are natural for pressed steel parts, also have a vibration-dampening effect on the entire cab construction, thus making it easier to design a quiet tractor cab. Mounted on a farm tractor of conventional design, the cab meets the noise rating number ISO N85.