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Technical Paper

Transmission Oil Degradation Warning Systems and Computing in Agricultural Tractors

2000-06-19
2000-01-1873
This communication examines three strategies of predictive lubricant monitoring and replacement, used for farm tractors or similar vehicles. These strategies optimise the draining periodicity. They are the off-line follow-up, the sensors follow-up and the analytical model follow-up. The implementation of the suggested analytical model will be discussed, on the basis of field collected data (on a series of tractors, either customer's or on loan). Regular oil samples, and significant ones carried out at the end of the study, were taken and analysed in order to predict the evolution of the lubricant characteristics. Extensions to the experimental study were carried out at the end of this work. They are discussed in the paper (FZG gear scuffing, 4 ball wear and EP…).
Technical Paper

Investigation of Package Bearings to Improve Driveline Performance

2000-06-19
2000-01-1785
The tapered roller bearings employed in axle centers for the pinion support are critical components in determining the noise, fuel economy and reliability characteristics of the vehicle. They represent a relatively complex mechanical and tribological system, with special requirements from the stiffness, lubrication and heat transfer points of view. This paper brings a contribution to the investigation of the intricate dependency between design parameters, environmental factors and the resultant performance of a package bearing in an integral double cup configuration. Axial compactness, reduced weight, and superior rigidity are only few of the multiple advantages recommending this type of double row bearings for automotive driveline applications. Different aspects related to the tapered roller bearing setting are analyzed in a theoretical and experimental manner, also under the consideration of the manufacturing and assembly processes.
Technical Paper

Steering Performance Evaluation - Heavy-Duty Highway Tractor Wander Test

1999-11-15
1999-01-3764
Heavy-duty highway tractors are the topic of various studies and tests to understand vehicle wander as a contributing factor to driver fatigue. Subtle variations in steering system characteristics can create measurable differences in performance, and operators may have different subjective opinions of the same system. This paper's purpose is to examine wander test setup and data analysis for tests conducted on an International® Model 9200 tractor-trailer at the Navistar Technology and Engineering Center in Fort Wayne, Indiana. Instrumented data and subjective ratings were collected using five power steering gears, evaluated by six drivers, operating over a specific test route.
Technical Paper

Multi–Branch Torsional Vibration in Geared Rotating Systems

1999-11-15
1999-01-3746
Torsional vibration usually causes noticeable sound disturbances, mechanical shakings, and component fatigue problems. It exists at one or more periods of the operating range in torsional systems. Determination of critical speeds or torsional natural frequencies in a design stage makes it possible to avoid early fractures and costly repairs of the machinery. In this paper, the method for predicting speed–related excitation frequencies of complex rotating systems is discussed and the computer program is developed and tested by actual examples. The natural frequencies and mode shapes of multi–branch torsional vibration systems with one or more junction points are calculated. A user–friendly graphic interface for modeling is presented. Some practical examples are given and the results of the simulations are compared to those obtained analytically as well as those given in references.
Technical Paper

Environmental Standards for Biodegradable Hydraulic Fluids and Correlation of Laboratory and Field Performance

2000-09-11
2000-01-2543
Biodegradable hydraulic fluids have been introduced relatively recently and, initially, acceptable environmental performance and technical performance were neither well specified or controlled. Over the past few years, many standards and specifications have been written, especially in the area of biodegradability and ecotoxicity. Technical performance test requirements are emerging more slowly, however, and there is still some doubt over appropriate tests and limits for some performance areas. The proliferation of standards is confusing to both the product developer and fluid user. This paper summarizes the common biodegradability and ecotoxicity elements in the main environmental performance standards. It also discusses appropriate laboratory performance tests for oxidation stability, hydrolytic stability and wear, and sets acceptable limits in these tests, based on correlation of lab and field performance of two synthetic ester based hydraulic fluids.
Technical Paper

Performance of High Oleic Soybean Oil Based Hydraulic Fluids in Long-Duration Pump Tests

2000-09-11
2000-01-2556
Tests were performed to evaluate the performance of high oleic soybean oil-based hydraulic fluids in long-duration pump tests. Formulations for a conventional hydraulic fluid and a food grade fluid were operated in a low volume hydraulic system for up to 1000 hours. Traditional measures of fluid performance including pump wear, total acid number and viscosity change indicate overall acceptable fluid performance. In addition, a methodology for studying the time-dependent change in pump cartridge surface roughness was investigated. Results indicate that changes in pump roughness correlate with changes in other traditional measures of fluid performance and this additional wear parameter could be useful in developing models to better understand the time-dependent behavior of the system and thus to guide efficient development of enhancements to the oil-additive package.
Technical Paper

Steel Quality Requirements for Heavy Duty Off-Highway Gearing

2000-09-11
2000-01-2566
The bearing industry has long recognized that reducing the total number and size of large aluminum oxide inclusions proportionately increases contact fatigue life. Improved geometric accuracy and surface finish on heavy duty off-highway carburized gearing has increased the significance of oxide inclusions in nucleating contact and bending fatigue fractures. While modern steel making technology can regularly provide high quality steel with controlled cleanliness, the absence of an industry standard specification makes procurement difficult. Key quality and steel cleanliness requirements have been written into CNH's alloy gear steel specification. A detailed questionnaire has been developed and is utilized to help identify steel mills that have the modern equipment and processes needed to produce high quality gear steel.
Technical Paper

Comparison of Plain Bushing Technologies for Reduced Grease Consumption in Construction Equipment

2000-09-11
2000-01-2603
In construction and agricultural equipment, joints using plain bearing / shaft assemblies need to fulfill demanding requirements regarding reduced grease consumption and maintenance, load bearing capacity, resistance to shocks, overloads and abrasion. The behavior of an innovative bearing design, based on the combination of steel as core material, special surface topography and high technology surface treatments is studied. Surface topography, composition of the friction layer and base material turn out to have a considerable influence on the behavior of the joint. This new bearing design is compared with other common industrial bearing technologies and is found to be the best compromise in terms of resistance to adhesive and mechanical wear under high load oscillatory motion.
Technical Paper

Development of Heat Resistant Long Life Through Hardening Bearing Steel (STJ2)

2000-09-11
2000-01-2602
The development of a long life rolling element bearing for use under severe conditions is fundamental and important technology from an economic and environmental standpoint. Previously, NTJ2 was developed as a semi-heat resistant long life bearing steel, using silicon as an alloying element to enhance its heat resistance and life. It is thought, though, that the demand for a bearing material that can withstand higher temperatures and have a longer life than NTJ2 will be needed in the future. Thus, a new heat resistant, long life material called STJ2 was developed optimizing the alloying elements in the silicon-alloyed bearing steel. The new steel has good dimensional stability to 250°C, long life and is very resistant to surface damage.
Technical Paper

Heat Exchangers for Heavy Vehicles Utilizing High Thermal Conductivity Graphite Foams

2000-06-19
2000-01-2207
Approximately two thirds of the world's energy consumption is wasted as heat. In an attempt to reduce heat losses, heat exchangers are utilized to recover some of the energy. A unique graphite foam developed at the Oak Ridge National Laboratory (ORNL) and licensed to Poco Graphite, Inc., promises to allow for novel, more efficient heat exchanger designs. This graphite foam, Figure 1, has a density between 0.2 and 0.6 g/cm3 and a bulk thermal conductivity between 40 and 187 W/m·K. Because the foam has a very accessible surface area (> 4 m2/g) and is open celled, the overall heat transfer coefficients of foam-based heat exchangers can be up to two orders of magnitude greater than conventional heat exchangers. As a result, foam-based heat exchangers could be dramatically smaller and lighter.
Technical Paper

Development Trends in Bus Manufacturing

2001-10-01
2001-01-3330
The vast majority of all buses built today are composed of a steel chassis containing the Diesel-engine, gearbox and the axles with a steel body attached to the chassis. One route of development is exploring the use of clean fuels and alternative engines. Among the clean fuels compressed natural gas, liquefied petroleum gas and methanol must be mentioned. Representatives of alternative engines are Diesel-electric systems and fuel cells. Another route is light weight design of the body. For more than 30 years some manufacturers offer aluminium structures to be mounted on a steel chassis. In order to overcome the impact of the high cost of aluminium against steel, innovative assembly techniques have been introduced to shorten the assembly work. In a following step so called hybrid concepts have been introduced, where big surfaces such as floor and roof are made as one piece sandwich panels. In advantageous configurations such buses can be built without chassis except axle modules.
Technical Paper

The Cargo Truck Cabin Production Partnership

2001-03-05
2001-01-3881
The transfer of the Trucks and Pickup Trucks operation from Ipiranga to São Bernardo do Campo (SBC) enabled the Ford Motor Company Brasil Ltda. to implement an extremely efficient Cargo Truck production line. This operation has achieved high productivity rates, thanks to the partnership undertaken with Usiparts, a subsidiary of the Usiminas group. This partnership process constituted a novel development for the organization since, for the first time in Brazil, Ford transferred a core operation to a partner, which is responsible for the entire cabin production chain, comprising the manufacture of stamped parts (which makes use of Usiminas' own steel), sub-assembling of panels, framing and welding of the cabins, sealing and painting. Usiparts is responsible also for building the new subassembly fixtures and cells, having additionally provided the required investments.
Technical Paper

Development of Application Technique of Aluminum Sandwich Sheets for Automotive Hood

2000-06-12
2000-05-0237
Objective of this study was to develop basic techniques in order to apply aluminum sandwich sheets for an automotive hood part. The aluminum sandwich sheet is the material fabricated by adhering two aluminum skins to one polypropylene core. When it has the same bending stiffness as a steel sheet, it is 65% lighter than the steel sheet and 30% lighter than an aluminum alloy sheet. Therefore, it is notified exclusively as good substitutive materials for a steel body to improve the fuel efficiency. Through aluminum sandwich sheet, however, it has relatively lower formability than that of the steel sheet for automotive application. In this study, we fabricated a prototype of the automotive hood panel to develop application techniques of the aluminum sandwich sheet.
Technical Paper

Application of X-Ray Measurement to Bearing Failure Analysis

1983-02-01
830825
X-ray measurement is a very useful tool for bearing failure analysis. Compressive residual stress is created under the bearing raceway if bearings are used under a contact stress higher than the critical value. Residual stress distribution measurement of a used bearing enables to presume contact stress in service. Half height breadth of diffracted X-rey also changes with the fatigue of the material. Therefore X-ray measurement may estimate the degree of fatigue of a used bearing. Fracture surface of a fractured bearing has sometimes a high tensile residual stress at the surface, from which we can presume the fracture toughness of the material and then calculate the fracture stress. X-RAY diffraction is a very useful tool for bearing failure analysis, because X-ray diffraction technique can detect sensitively macro and microscopic lattice changes of a surface layer of crystalline materials.
Technical Paper

Fatigue Life Estimation on HSLA Chassis Frame

1981-02-01
810358
Fatigue tests were performed on five kinds of fillet welded joints on 2.6 mm thick HSLA steel sheets, to evaluate the fatigue life of automotive HSLA chassy frame with different joint geometries under various loading conditions. Specimens were made by CO2 gas arc welding with 1.2 mm diameter wire. During the fatigue tests at stress ratio (R)=−1, dynamic strain was measured using a 3 mm strain gage cemented on the sheet surface nearest to the toe. Data were discussed by nominal stress as well as by local strain.
Technical Paper

Performance of Alcohol Blends in Diesel Engines

1981-04-01
810681
A normally aspirated, four-stroke diesel engine was tested under operation with two alcohol containing fuel blends. The fuels contained ethanol, butanol, heavy virgin distillate, diesel Nos. 2 and 4, and a cetane improver. The proportions of the components were selected to give blends with properties within the range of diesel No. 2. The final blends contained 25 and 43.7 percent alchohols. Test results showed a loss in power due to the reduced heating value of the blends, and some deterioration of performance at light loads. At intermediate to heavy loads, satisfactory performance was obtained.
Technical Paper

Friction Welding-Its Mechanical Properties

1981-04-01
810692
The mechanical properties of friction welded joints have been determined through tensile, fatigue, photoelastic and residual stress analyses. These properties and the testing methods involved are defined and the results compared to like joints welded with the flux-cored, gas-shielded process.
Technical Paper

High Concentration Ethanol-Diesel Blends for Compression-Ignition Engines

1983-09-12
831360
A fuel blend containing 30 percent ethanol, diesel fuel and additives was tested in a diesel tractor to determine its effect on engine performance and durability. Uprating the delivery of the fuel injection pump was found to be a practical method of restoring the 11 percent power reduction caused by the lower heat content of the blend. Operation of the tractor under on-farm conditions for alternate 100 hour periods totalling 2000 hours on diesel fuel and on the blend revealed no noticeable deterioration in engine condition related to the blend.
Technical Paper

In-Situ Measurement of Fretting-Wear: A Design Approach

1983-09-12
831379
Fretting occurs in mechanical or structural joints that were not intended to move, relative to each other, but because of vibrational loads or cyclical deformation, experience minute cyclic relative motion. Fretting-wear develops as a form of wear that retains the majority of the wear debris within the contacting interface. Fretting-wear failure may be defined in functional terms of the normal approach accrued. The magnitude of normal approach due to fretting-wear can be measured in-situ as a function of cycles of operation. These data can be transcribed directly into design curves to enable prediction of impending functional failure in mechanical/structural joints subjected to fretting-wear. Supporting parametric data have evolved from these experimental investigations yielding further insight to the phenomenon of fretting-wear in steels such as SAE 1020, SAE 4340 and SAE 52100.
Technical Paper

Trials and Tribulations of Fatigue Testing of Bearings

1983-09-12
831372
This paper, while not intended to be a comprehensive guide to all of the details of fatigue testing of bearings, does give an overview of the basic considerations that must be addressed. Compromises are always made in fatigue studies, and this paper provides information on the associated implications. Included is a discussion on the life scatter normally encountered in fatigue testing, means and limits of accelerating testing, and comments regarding equipment and cost.
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