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Two new Caterpillar Wheel Loaders have been developed in the 1.2 cubic meter (1.5 cubic yd.) and 1.5 cubic meter (2.0 cubic yd.) bucket capacity categories. This paper provides a review of the design objectives and summarizes the design features included to meet worldwide manufacturing and marketing requirements.

ISO and SAE static sound power test methods are currently used for construction machinery. The European Economic Community sound committee has been developing a drive-by or simulated work cycle test method using a hemispherical array of microphones. The EEC method is inconsistent due to the changing test surface (moist sand) and the variables of outdoor testing: temperature, wind, and precipitation. The in-place-dynamic test method described provides a disciplined way to evaluate machines with moving track or wheels and operating hydraulic systems. The machine is slightly elevated, resting on stands, so that the wheels are off the ground or the tractor weight is off the track chain. Data obtained from track-type tractor, track-type loader, and wheel loader machines supports the validity of using an indoor, in-place-dynamic test instead of a moving, outdoor test. Results also show that using sound intensity instrumentation permits the option of testing in an untreated, indoor facility.

This paper details the design and features of the 651E, 657E, and 657E Push-Pull Wheel Tractor Scraper. Emphasis was placed on the availability, reliability, and serviceability of these units.

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.

A new Caterpillar Wheel Loader has been developed to provide a loader in the 2 cubic meter (2.5 cubic yard) bucket capacity-category. This paper provides a review of the machine design objectives and summarizes the design features included to meet worldwide manufacturing and marketing requirements.

THE HYDRAULIC SYSTEMS for the Caterpillar “G” Series Motor Graders were designed to provide for maximum operator comfort, ease of operation, and optimum control of the vehicle and implements. The use of high pressure closed center systems on these machines produces rapid system response and high hydraulic horsepower to the implement cylinders and motors, and operates with minimum size control components. Components were designed to meet specific system requirements for functional performance, reliability of operation, size and placement on the machine. System goals were met through the use of a variable displacement pressure compensated pump, controlled flow four-way implement valves, and a hydrostatic steering system.

The heavy-duty truck industry has seen the need for a change in the concept of transmission design for many years. Several improvements have been made and others attempted, but greater improvement is needed to match the engine's delivery to the vehicle's demand. Driver performance can be improved and fatigue reduced by lowering the effort and skill required to make smooth, consistent starts and ratio changes. This paper discusses a solution to this need in the design and development of a semi-automatic, pneumatically controlled, constant mesh transmission.

The 528 wheel skidder represents a second-generation machine designed and tested to satisfy the requirements of the large wood areas of the world. Numerous unique features were incorporated in the design to meet the special needs of the logging customer; these are described, along with the development program that yielded the present vehicle.

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.

Modern data acquisition methods combined with new testing and analysis techniques are revolutionizing product design and development. Detailed analysis of recorded vehicle drive-line data has given today's engineer new insights into drive-line dynamics. This paper discusses how vehicles can be analyzed as a series of torsional springs and inertia masses. A two axle, 300 hp, 15 cu yd earthmoving tractor scraper (model 621) is used to illustrate significant factors. Main emphasis is on drive-line resonant torsional vibrations and shock loading. Diesel engines as torsional vibration exciters and transmission clutches as the major shock load producers are covered in some detail. How analog computers can effectively be used to facilitate vehicle development is briefly discussed.

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.

Two high specific output diesel engines designed for the Military -- the LVDS-1100 and LDS-750 engines, which are of V-8 and 5-cyl in-line configuration, respectively -- were developed by Caterpillar Tractor Co. under contract with U.S. Army Tank Automotive Center at Detroit Arsenal. This paper covers the development work, also sponsored by ATAC, required to adapt these engines for operation using regular grade gasoline in addition to the diesel and CIE fuels for which they were originally designed. Test techniques used, a description of some interesting combustion systems tried, and data obtained with the selected arrangement are included. The engine has excellent performance and starting characteristics with any of the three fuels.