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Development of more fuel efficient passenger vehicle engines based on lean burn technologies presents several challenges for controlling the emissions of regulated pollutants. Thus far, the emphasis has been on the selective reduction of NOx in the presence of excess O2. However, certification of vehicles based on lean burn technologies, whether gasoline or diesel, will require compliance with all regulated gas emission levels. Current working hypotheses on the origin of activity in lean NOx reduction catalysts will place strains on other aspects of the overall emissions system. Using the FTP-75 certification cycle as a basis for evaluation, the implications of using effective lean burn catalysts will be discussed. In particular, the requirement of ultralow hydrocarbon emissions has invoked strategies seemingly contradictory to the effective use of lean NOx catalysts. Possible alternative solutions and their consequences will be discussed.

The inefficient use of fuel by small 2-stroke powered 2-wheel vehicles results in high releases of hydrocarbons and carbon monoxide to the atmosphere. The presence of significant levels of oxygen (O2) in the exhaust stream creates an environment that is favorable for the use of catalytic aftertreatment to oxidize hydrocarbons and carbon monoxide to carbon dioxide and water, thereby eliminating or reducing the deleterious nature of 2-stroke engine exhaust emissions. This investigation examines the impact of catalyst formulation, operating temperature, and exhaust gas composition, on the performance of catalysts designed for use with these small 2-stroke power plant applications. It is demonstrated that catalysts can be formulated to possess specific performance objectives through the appropriate combination of noble metals and washcoating components. The non-noble metal components of a catalyst formulation are observed to be crucial to catalyst performance.

Urban buses are logical candidates for catalytic trap oxidisers (CTO's). Smoke and particulates present more acute problems in an inner city environment than on open roads, while on the other hand urban bus operation gives better chances of succesful regular regeneration than long-distance truck operation. With the support of the Dutch Ministry for Environmental Protection two CTO's are tested in urban bus operation in the city of Rotterdam. The program comprises extensive mapping of the exhaust gas quality at the start (gaseous emissions, smoke, particulates, sulfate and aldehydes) and regular monitoring of durability aspects at 30,000 km intervals. This paper presents the results of the first evaluation.

This paper introduces a new concept for the identification of automatic transmission gear trains. It describes the use of kinematic graphs to separate the topological structure of the gear train from its function. Using this method, it has been shown that known epicyclic automatic transmission gear trains can be classified in a systematic and unbiased manner. This procedure allows transmission mechanisms which have different gear arrangements to be compared on a uniform basis so their similarities and differences can be identified. It has been shown previously that there are 80 non-isomorphic displacement graphs from which all of the six-link, one-degree-of-freedom gear trains can be constructed. Here we show that there are seven non-isomorphic displacement graphs from which all epicyclic-type automatic transmission gear trains with up to six links and with four or more coaxial links can be derived.

Design features of the 100 ton electric drive truck developed by Caterpillar are discussed. Salient features of this vehicle are its power-weight ratio which is equal to or better than many small vehicles, and its maneuverability which enables it to turn within a 52 ft SAE circle. Two additional items mentioned are the use of electric power for smooth shifting of the vehicle and oil-cooled friction brakes for control of the truck under any stopping or retarding requirement. Present testing indicates this vehicle will make a worthwhile contribution to the better handling of construction material.

The purpose of this paper is to describe the design, development, and performance aspects of the Caterpillar 3176 diesel engine. The 3176, named for its displacement (1.7 liters per cylinder) and the number of cylinders (6), is a four-stroke-cycle, in-line engine with electronically controlled unit injection, turbocharging and Air-to-Air AfterCooIing. The 10.3 liter (629 in3) displacement engine was developed primarily for heavy duty on-highway truck applications, and will initially have power ratings from 187 kW to 242 kW (250-325 hp) at 1700 to 2100 rpm. This paper highlights several of the engine's design features which reduce fuel consumption, emissions, size and weight, while providing performance and durability characteristics comparable to larger displacement engines.

Caterpillar recently introduced its first backhoe loader - a significant extension to the existing product line of construction equipment. It is a highly versatile machine entering a well-developed marketplace. This paper describes design considerations, the development program, and vehicle design features associated with the 416 Backhoe Loader.

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.

Caterpillar has introduced a new off-highway mechanical drive truck in the 130/150 ton class utilizing the latest technology. This truck is an extension of Caterpillar's current truck line and it provides hauling performance comparable to the smaller 85 ton trucks. Since most of the major components are new designs, a comprehensive test program was completed prior to production. This paper describes the 785 Truck, several of its engineering features, and the development program it underwent.

Two new vehicles have been added to the line of Caterpillar wheel tractors and self-propelled compactors. The 814 wheel tractor is rated at 170 hp and weighs 41,000 lb. The 815 compactor is rated at 170 hp and weighs 38,000 lb. This paper deals with the steps that were taken to achieve the design objectives and presents a general description of the two new machines.

A new Caterpillar Wheel Tractor has been developed as a replacement for the original 834. This paper explains the vehicle objectives, summarizes the development program and provides a comprehensive review of the major features of the 834B Wheel Tractor.

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.

A new Caterpillar Wheel Loader has been developed as a replacement for the 966C. This paper explains the vehicle design objectives, summarizes the development program and provides a comprehensive review of the major features of the 966D Wheel Loader.

A new Caterpillar Wheel Loader has been developed as a replacement for the 980B. This paper explains the vehicle design objectives, summarizes the development program, and provides a comprehensive review of the major features of the 980C Wheel Loader.

A new Caterpillar Wheel Loader has been developed as a replacement for the current production 988. This paper provides a review of the machine objectives, summarizes the development program, and provides an introduction to the major features.

The Caterpillar D11N Impact Ripper has been introduced, extending the D11N tractor ripping capability beyond that of any previous ripper. This Impact Ripper displaces the blasting of previously unrippable rock in applications around the world. This paper describes the production design features, development program, and demonstrated performance of the D11N Impact Ripper.

The D7H Track Type Tractor (215 HP) has been developed as a replacement for the D7G (200 HP). This paper explains the vehicle design objectives, summarizes the development program, and discusses the D7H's unique features.

Caterpillar has introduced a new concept that shatters previous ripping limitations. The D9L Impact Ripper has extended the ripping capacity and productivity of the standard ripper tractor in heavy construcion, mining, and quarry applications. This paper describes the design objectives, development program, component selection, and the demonstrated productivity of the D9L Impact Ripper.

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 200 kw gas turbine engine power package has been developed. This is a complete unit containing the engine, reduction gear, power generator, and all necessary accessories and controls. This unit will be applied in continuous duty applications when there is a demand for exhaust heat recovery or in intermittent standby power applications. Power output and heat recovery characteristics are of interest in studying possible applications.