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Manual transmissions are used in a wide range of automotive applications such as commercial vehicles like trucks, buses and pick-ups as well on passenger car market. On manual transmissions is very common to use helical gears to transmit torque. Some of typical failure modes of these gears are tooth breakage, pitting and scoring. The objective of this paper is to present a case study of helical gear scoring issue on manual transmission and the design changes implemented in order to solve it. This material also shows the ultimate consequence of scoring problem on gear life and the co-relation of the part heat treatment case depth specification on this failure mode.

The challenge to develop a shifter system that achieves a better comfort on shifting gears in manual transmissions is mainly concerned to the subjectivity of the parameters involved, which are strongly based on perception of each customer. This work aims to explore these subjective quality requirements and identify their relation to engineering design parameters. A revision of previous studies on comfort and quality on shifting gears, semi-structured interviews and data from specialized magazines reports are used to define procedures and samples for experimental data acquisition. The results reveal important connections between quality on shifting gears and some design parameters of shifter systems.

At present in the United States, passenger car manual transmissions are almost exclusively of the strut type blocking synchronizer. General design parameters for this type of synchronizer, including formulas, present design practices, methods of evaluation, and variables that most affect synchronizer performance, are presented.

This paper aims at detailing the synchronization process step-by-step, delivering valuable recommendations on manual transmission synchronizer design. In order to do so, an objective description on the purpose of synchronization, its concepts and operation on manual transmissions is included. This work also portraits how the transmission components and the gearshift lever work together to provide a smooth ratio change.

In this paper, updated pilot/display/aircraft analysis techniques are applied to the problem of turbulence upset. In the course of an investigation of standard operating procedures and current autopilot turbulence modes, it was found that an improved turbulence penetration system is needed. A simulation was conducted to evaluate the turbulence autopilot and flight director concepts. It was found that an energy management system comprising the integrated autopilot and thrust director provided the greatest decrease in pilot work load and improvement in performance.

The Orbital Replaceable Unit (ORU) Transfer Device is a compact and mobile space crane that astronauts will use during extravehicular activity (EVA) assembly and maintenance tasks on the International Space Station (ISS). The ORU Transfer Device, herein referred to as the OTD, utilizes an articulated telescoping boom attached to a stanchion and will typically be mounted and used on the Crew and Equipment Translation Aid (CETA) cart. During EVA assembly and maintenance missions the OTD will be used to transfer ORUs to and from the CETA cart, storage locations and planned worksites along the space station truss. A key design requirement of the OTD is that it can be manually operated by an unrestrained astronaut without using electrical power.

This paper discusses the important issues associated with implementing a fiber optic lighting system within the automotive environment. Generic distributed lighting technology advantages are defined and shown how they impact the vehicle systems. The paper focuses primarily on the manufacturability and assembly issues that are pertinent to the successful production application of this technology. Conclusions drawn from the discussion illustrate a bright future for the technology, once the technical issues are all resolved.

Antennae on modern telecoms satellites are subject to extra heating by illumination of both direct sunlight and reflection from the optical solar reflectors (OSRs). One method to decrease the temperature of the transponders is to modify the direction of the reflected light from the OSRs. OSRs with a large diffuse component of reflectance have been successfully manufactured. In this paper, we describe the manufacture and characterisation of the optical properties of these diffuse OSRs.

A number of prototype automotive interior trim products were developed from polyurethane-cored headliner scrap by utilization of isocyanate-based binders: 1) rear-seat-to-back-window trim panels (Deville and Eldorado Chimsl covers), 2) package trays (Neon PL-tray, Buick/Oldsmobile G-trays), and 3) sun-shades (Accord/Acura sun-shades). The technology for the manufacture of these products is outlined in this paper as well as their mechanical, acoustical, and other properties relevant to the automotive interior trim applications.

METHODS of manufacture and materials used for turbine blades, buckets, and vanes are described in this paper. Precision forging of these turbine parts is the preferred method. Other manufacturing techniques discussed here include the lost-wax, frozen-mercury, and lost-plastic processes and sintered powder metallurgy, casting, and fabrication. Use of specially designed equipment has resulted in vast improvements in some operations. The paper discusses such new material developments as reinforced plastics, cermets, and titanium in addition to listing the standard alloys used for turbine buckets, blades, and vanes. A description of current British practices is also included.

The meltable metal core process is examined as a means of producing cost-effective, composite on-engine components. Each step of the process is studied using water pump housings molded from Rogers' Moldable Phenolic Composites (MPC™) with Sn/Pb/Sb alloy cores. With proper control of core surface, core temperature and mold temperature, excellent moldings can be produced at tight tolerances. Process data and control techniques are presented.

Composite Propeller Blades have been developed and are now in production for the new generation of turbo-prop commuter aircraft. The method of manufacture utilises special tooling and a resin injection process specifically developed to produce composites with good fibre volume fractions and correspondingly high structural properties. Quality Control and NDT methods have been developed to ensure a high quality product, which involves the use of Ultrasonic, Radiographic and Vibrational Analysis. Certification of the Composite Propeller has necessitated rigorous structural and environmental testing of the finished blades, involving specialised rigs and techniques. Material properties have also been evaluated for static fatigue capability, and the effect on these properties of long term exposure to various climatic conditions is underway.

THIS paper describes production methods of pistons characterized by an elliptical skirt having a slot or slots that affect the form of the piston under operating conditions, as practiced at the Plymouth Motor Corp. Design changes that have affected production technique and changes in production practice itself are important recent developments in aluminum-alloy pistons. Foundry data include a description of the small open-hearth furnaces and the permanent molds with collapsing cores employed. Other foundry operations - heat-treating, sprue cropping, hardness testing, and rough machining - are dealt with fully. In this foundry an output of 18,000 pistons per 24-hr. day can be maintained in an area of 1,200 sq. ft. This type of piston fits the cylinder bore with about a 0.001-in. clearance in a cold motor, the expansion at operating temperatures being compensated for in the slotted skirt. This skirt is in the form of an ellipse whose minor axis is 0.011 in. less than its major axis.

From efforts to utilize waste wood fiber more fully from the lumber industry has come a substrate now widely used for interior trim parts in automobiles. Hardboard results from the separation of wood fibers, formation of the fiber into a mat, and subsequent consolidation with heated presses. Humidification of the pressed board followed by trimming and edging complete the manufacturing process of hardboard. Environmental improvement is a continuous program in the hardboard industry and has resulted in the development of a number of salable byproducts from mill residue.

A commercial process for composite (thermoset) materials has been developed. Key advantages are light weight, low molding pressures, and the ability to accommodate two or more types of reinforcements and one or two resin systems. Partial or complete encapsulation of light-weight cores with tough FRP skin can be obtained. Current and potential applications include light weight, structural automotive, and industrial fiberglass reinforced composites.

The basic raw material used in manufacture of fiberboard is cellulose fiber which is obtained from trees and/or reclaimed (waste) paper. Cellulose fibers are obtained from trees by the “pulping” operation which involves debarking, chipping, and cooking with chemicals to separate the cellulose from other wood components. Cellulose fibers are obtained from reclaimed paper by mechanical repulping in water. Cellulose fibers, once pulped, go through the stock preparation phase where they are cleaned and sent through a refining stage. The conditioned fibers are sent to the paper machine in a water slurry for conversion to paperboard. The paper machine is a large controlled water removal system having four distinctive manufacturing steps: mat formation, pressing, drying, and calendering. The paperboard from the paper machine is sheeted or wound in rolls. It may be sold in this condition or undergo further processing such as laminating or coating before it is sent to the automotive fabricator.

Hydrostatic extrusion has been demonstrated to be a promising method for the manufacture of tubing in a variety of materials. In development studies at Battelle, the process has been used to fabricate tubes from alloy steels, hard aluminum alloys, and titanium alloys. This paper describes the equipment and techniques utilized in hydrostatic tube extrusion, and discusses how the process fits into commercial tube production operations. The potential capabilities for applying the hydrostatic extrusion process as a substitute for hot extrusion or as a substitute for conventional drawing or tube reducing of tubes produced by other means are summarized for a variety of materials.

OUTSTANDING characteristics of magnesium castings are light weight and excellent machinability. Production has increased from about 10,000 lb. in 1925 to approximately 800,000 lb. in 1936. Differences in foundry methods from those practiced for other common metals are pointed out. The mechanical properties are specified, and inspection methods are described. Suggestions are given for proper design of castings. Machining methods and tool design suitable for obtaining the smooth finish, the speeds, and economies that are possible for magnesium-alloy castings are described. Careful painting under approved methods is recommended. Applications of magnesium castings for many parts of aircraft engines, for parts in the fuselage, and in such accessories as aircraft landing wheels and starters are listed, along with other typical applications.