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Gearing load spectra data collected under actual working conditions help a designer predict the fatigue life of power train components. Considerable time was required in the past to collect and reduce these data to a form suitable for design use. A vehicle mounted instrumentation system consisting of a strain gaged shaft, a shaft encoder-slip ring assembly, and an amplitude distribution analyzer, was developed which performs load measurements. At the test's conclusion, it provides a spectrum analysis in printed histogram form.

THIS paper presents results which will answer many of the problems facing an engine manufacturer in the selection of the most suitable types and sizes of superchargers to use with a line of engines. Although performance curves of production model diesels are available, decisions are still needed in choosing peak supercharging pressures, drive means, and size and effectiveness of intercoolers, if any. The author describes the use of a typical model to determine response to variation in intake and exhaust conditions, resulting in data which will assist in evaluating engine potentials with any system of supercharging. Thus, supercharger selection for a particular line of engines is aided by knowledge of engine characteristics as a second-stage compressor.

This paper first discusses the loads of major significance to various machines and machine parts, and second, considers available methods of measuring, analyzing, and presenting information on loads and stresses. Various engine and machine components are examined from standpoints of loading methods and which loads are likely to be critical on each component. Interrelations between components and machines are also discussed. Tools and methods available to the load and stress analyst are described, with particular emphasis on choices available in methods, instrumentation, and presentation of data. Reasons for preferences in particular situations are given.

SETTING ratings for diesel engines takes laboratory testing and field experience for critical parameters such as smoke, piston temperature, and exhaust temperature. Rating is based upon theoretical considerations, plus the approval of the engine itself. Factors in rating considerations include a knowledge of the application of the engine, and whether its use is to be intermittent or continuous. Ratings by the manufacturer are not always accepted by the engine user, however. The user will run the engine at the load most profitable for him, which may be above or below that recommended by the manufacturer.

Advance in earthmoving technology has made necessary a corresponding advance in cutting edge technology. In adopting the concepts of matching the cutting edge to the machine, or possibly the job requirements of the machine, in rare instances it is found that the cutting edges employed in the 1930's and 1940's are satisfactory; however, in general, the increase in horsepower and carrying capacity of earthmoving machinery has necessitated a vast increase in the strength and wear properties of the cutting edge. The development of these properties, based on academic, laboratory, and field precepts, has advanced hand-in-hand with machine developments.

A new friction welding process, Caterpillar Inertia Welding, is described in this paper. The two distinguishing characteristics of this form of welding are a continuously decreasing rotational velocity and a continuously changing torque at the weld interface. This enables the forging of many previously “difficult-to-weld” materials, such as superalloys. Such welds also exhibit excellent fatigue properties. Because this process produces high strength bonds in dissimilar materials, the designer is able to create composite parts using the special properties of each material in response to the needs of the design.

A single-shaft, simple-cycle gas turbine engine has been developed to power 200 kw alternators for standby power and for applications where heat is needed. The engine was designed to be sold and serviced by distributors of earthmoving and industrial machinery. Where feasible, design practices of industrial piston engine powered generator sets were incorporated to facilitate installations of combinations of engine types, and to limit novel and unfamiliar features of the basic turbine engine to those that were considered essential. Individual components and complete engines, initially developed by a research group, have been subjected to a wide variety of laboratory tests to measure performance and develop reliability.

Inertia welding is a friction welding process using energy stored in a rotating mass as the source of heat and mechanical work. The process has been described in previous publications. The state of development of this manufacturing process, with respect to complexity of design and dissimilar metal welding, is the subject of this article. The successful applications of inertia welding now in production establish the utility of this versatile process while current developments portray exciting future possibilities.

The Cushion Hitch is a unique application of vibration absorber theory to a self-propelled tractor-scraper. The scraper mass is utilized as a damper for suppressing predominate bouncing motions of the tractor unit. A more comfortable and safer operator ride, with increased productivity, results from the Cushion Hitch application. This paper describes development of the early prototype design as well as the final production version. Particular emphasis is given to both the hydraulic and the structural characteristics of the system.

A new 2-ring piston package has been developed which has proven successful in internal combustion engines. The need for a compact piston arrangement is discussed along with the steps followed to arrive at excellent oil economy. The paper presents other advantages related to cost savings, lower wear, and reduced engine friction. The paper discusses applications of the compact piston package along with its advantages in designing compact engines.

This Paper: 1. Shows that the present spherical rod end manufacturer's rotational tests, which are intended to select the best bearing material, do not necessarily select the best materials for the push/pull linkage requirements of earthmoving machinery. 2. Emphasizes the need to perform push/pull comparative testing as defined in SAE J1367 on spherical rod ends to determine acceptable materials for earthmoving equipment application. This test is in contrast to rotational testing presently being performed by spherical rod end manufacturers.

The small wheel type loader has seen its application range extended such that it is now one of the most versatile machines in our industry. However, its effectiveness in tasks other than bucket loading is limited. In order to provide improved tool control characteristics that contribute to efficient multi-task capability, it is necessary to design these characteristics into the base vehicle. The Integrated Toolcarriers recently introduced by Caterpillar fulfill this requirement. This paper discusses the design objectives and summarizes the development program which preceded their introduction.

For some time, Caterpillar Tractor Co. has been marketing a new transmission control system for wheel-tractor scrapers and off-highway trucks. The new system is composed of an electronic microprocessor control box coupled with an individual clutch modulation hydraulic control. This system has resulted in increased vehicle productivity, improved reliability and serviceability, decreased complexity, and increased commonality of parts. This paper describes the concept, design, and test and evaluation process used to develop the new controls before production.

TVA is an interactive computer program which performs a Torsional Vibration Analysis on lumped mass systems which contain torsional degrees of freedom. This program has two fundamental analyses. The first is Normal Modes which analyzes the natural unforced undamped behavior of the system to give natural frequencies and mode shapes. The second analysis is Frequency Response which analyzes the forced response of a damped system to give response results. TVA is used to analyze engine-auxilary equipment systems as well as vehicle drivetrain systems.

THE CATERPILLAR FOLDED CORE RADIATOR IS A NEW RADIATOR FOR VEHICLES AND STATIONARY ENGINE APPLICATIONS. THE MAJOR OBJECTIVES OF THIS DESIGN ARE TO GIVE THE USER AN INCREASED VALUE COOLING SYSTEM BY REDUCING RADIATOR REPAIR COSTS AND IMPROVING AIR-SIDE PLUGGING RESISTANCE. AS WELL AS PROVIDE THE VEHICLE DESIGNER WITH INCREASED APPLICATION DESIGN FLEXIBILITY. THIS IS TO BE ACCOMPLISHED WHILE MAINTAINING PERFORMANCE AND LIFE GOALS ASSOCIATED WITH THE CONVENTIONAL RADIATOR. THE FOLDED CORE IS A MODULAR DESIGN HAVING THE MODULES INSTALLED AT AN ANGLE TO THE FAN AIR STREAM RESULTING IN THE FOLDED APPEARANCE. COMMON MODULE SIZES ARE USED ACROSS THE MANY RADIATOR APPLICATIONS REDUCING INVENTORY REQUIREMENTS AT THE ASSEMBLY PLANT AND PARTS DEPOTS AND INCREASING INDIVIDUAL MODULE PRODUCTION VOLUME. THIS RADIATOR DESIGN IS REVIEWED FROM CONCEPT TO PRODUCTION.