Search Results

New applications of data processing to truck maintenance give fleet managers an excellent means of reviewing maintenance experience and controlling maintenance costs. Classifying each maintenance experience according to the reviews to be made, and making a data processing record of each one, creates report patterns that uncover repetitive repairs, inefficient procedures and practices, and inappropriate component selections. This paper describes the benefits of such a system and discusses the considerations, procedures, and problems involved in setting it up. The paper also points out the basic simplicity of the data processing techniques used and their applicability to fleets of all sizes.

The general design parameters used to design the aluminum semitrailer closed top van for highway operation are described in practical terms. The discussion deals primarily with vertical loading (pay-load) and side panel design concepts; design considerations presented are general in nature. Final design must include many factors too lengthy to include. This paper does not describe in detail the actual engineering theory of design, but uses simplified analogies so that the basic concept can be understood and, thereby, encourage repair procedures compatible to original design.

This paper describes the design, construction, and performance features of two ranges of compact, high specific output diesel engines designed for stationary, mobile, and marine applications, and capable of operation in severe climatic or service conditions. The description also shows how design simplicity and maximum interchangeability of components have been combined to ensure easy maintenance.

The engineer troops in Vietnam have had to cope with a number of problems caused by the rapid buildup of troops, the complexity and wide variety of equipment in use, and the resulting high level of skill required of operator and maintenance personnel. This paper describes some of the equipment and procedures developed by USAEDRL for ease of assembly and maintenance, including the sectionalizing of vehicles. The author also outlines maintenance problems encountered in the field, particularly on hydraulic systems and the overall problems of quality control.

With the advent of ever larger mobile machines in the earthmoving industry new methods of steering control had to be developed. Three basic systems which had sufficed in the past were mechanical, electrical, and hydraulic power steering mechanisms. This paper describes a new hydrostatic power steering system which appears particularly applicable to large off-road construction machines. Basic features of the V2 Hydraguide system are discussed. It is believed this system meets the general requirements for a high-flow steering unit and represents a new era in controlability for articulated vehicles.

The design requirements for the frame as a load carrying member are discussed in relationship to a highway truck and its basic vehicle package. The theoretical and experimental procedures are given in detail to demonstrate the techniques for frame design. The features of a method to laboratory test a frame with correlation to service miles is discussed.

Methods and equipment have been developed to sculpture aluminum honeycomb core. Three special honeycomb mills, hand-step cutting equipment, and a composite tooling material are being utilized to contour machine aluminum honeycomb on a production basis.

Spark plug heat range requirements, preignition limits, and ignition voltage requirements were investigated in several liquefied petroleum gas (LPG) fueled engines. These tests show that ignition voltage requirements both for cold starting and for running are considerably higher than with gasoline. It is also shown that very cold running spark plugs are both undesirable and unnecessary with LPG fuels. Spark plug design can be utilized to reduce voltage requirements and to improve the overall performance of these engines. Projected core nose type spark plugs may offer additional performance benefits in LPG tractor engines.

Operating year round in Labrador and Northern Quebec has necessitated the special use of alloy metals, natural rubber compounds, ancillary heating, lubricants, and antifreezing agents in the Iron Ore Co. of Canada's mining equipment. This paper describes the selection of these materials and their application to cold climate operations in recent years.

This paper discusses the possible impact of the FM tape recorder and servo-hydraulic actuators on the testing of automotive structures. The use of tape recorders and automatic data reduction systems will permit more accurate definition of service conditions and properly “set-the-stage” for laboratory testing. Servo-hydraulic strokers should encourage better laboratory simulation because of their great flexibility. Test set-up time is reduced, fixtures can be simplified and load control is more precise. Simultaneous multiple inputs can be controlled as to amplitude and phase relationships.

The various types of nonmetallic friction materials used in oil and their important characteristics are given. The effect of grooving on clutch plate operation, thickness considerations for design, and the characteristics of mating surfaces are covered. The oil flow required and the effect of different oils on frictional properties are discussed. The newer paper type materials with high coefficients of friction and the considerations involved in their use are described, as are the requirements for the reaction plates to operate with them. The effect of temperature on clutch operation is considered and a method is given for approximating temperature rise in a clutch.

The three major problems with the side mounted PTO are: the variety of PTO’s required, clearance for mounting, and power output available. PTO’s have generally not been rated above 150 ft-lb torque with the SAE 6-bolt mounting. Using tooth loading as the selection guide rather than engine ratio, equipment with 258 ft-lb torque requirements is being successfully used. The recommended solutions to the problems are more standardization in transmission drive gears and the provision of adequate clearance by the chassis manufacture.

The Army is considering a four-category system of trucks for the Field Army, namely, Military Hi-mobility Tactical, Military Tactical Standard, Quasi Military, and Commercial Administrative Types, which are broadly described and charted herein. Commercial trucks are generally not considered adequate for Field Army use; however, this proposed overall four-category system of trucks, potentially, can offer real military effectiveness at lowest cost. The success of the proposed system will largely depend on well supported and thorough truck engineering system design and cost studies to insure effective product implementation.

The author discusses the use of electrical discharge machining in research, production, and tool work. Specific considerations determining the selection of proper electrode design and construction particulars to fit a need are presented. Illustrations depicting the use of EDM electrodes in production and tooling are included. Specific advantages to be realized by proper use of EDM are outlined. A truly economic, high quality die can be obtained through use of EDM when the tool engineer makes proper use of this technique.

Tactical trucks are trucks that can travel where the conventional commercial trucks are immobilized by adverse terrain conditions and, for military use, must be able to withstand misuse, abuse, and neglect, yet still perform their mission. The eight-by-eight configuration evolved from the mobility requirements. Swimming capability, with payload, is a new requirement met by the trucks, 2-1/2 Ton, 8×8, XM410E1 and 5 Ton, 8×8 XM656. Curtailment of military personnel has resulted in the availability of less maintenance and supply support. Consequently, these new 8×8′s have been designed for a minimum of maintenance by using very durable components, sealed units, and lubed-for-life-bearings.

The military problem of rapidly transporting 60 ton pay-loads over existing road networks in all parts of the world has yet to be solved. This paper presents a review of past history of transporters, both production models and development efforts. The basic missions of the vehicles are explained and the major requirements are reviewed. Several new and unique concepts for heavy transporters are presented.

Tractor dozers and bucket loaders require two exacting readjustments for every initial adjustment of the blade to make a smooth cut. The necessary precision of these blade adjustments at fast speeds is beyond the human capabilities of an operator. This paper explains how the blade readjustments are now being performed automatically, producing smooth cuts and permitting high speed blading. The accuracy of blade control provided by this system opens new avenues of applications and performance for tractor blading operations.

Discussion of improvement of truck ride, chiefly concerned with driver and passenger comfort related to road condition. The kinds of natural vibrations in vehicles which determine the quality of ride are discussed first, and then the sources of forces, both outside and within the vehicle in operation, which initiate the vibrations and establish their magnitude of motion.

The author discusses the six design parameters having the most effect on trailer towing characteristics. Effects of weight, balance, center of gravity, suspension system, aerodynamics, and construction or rigidity of both the chassis and body shell are evaluated in terms of trailer towability. An important consideration is that regardless of how well a trailer is designed, its ability to be towed effectively is dependent on the tow vehicle as well as on the type of hitch that is used.