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Video

Eco+ Solutions in High Performance Plastics from DSM for Automotive.

2012-05-22
DSM will present various application solutions in High Performance Plastics enabling to significant weight or friction reduction and thus to reduced fuel consumption and/or emission levels, and on top of that to lower system costs. Typical Eco+ Solutions Examples to be presented are: - Friction Reduction: Nylon 46 in chain tensioners yielding up to 1 % fuel reduction - Weight Reduction (metal-to-plastic conversion): Nylon 46 with long term temperature resistance upto 230 C in turbo components, Nylon 6 in oil pans/sumps, PET in plastic precision parts, Nylon 46 in gears, many other examples - Electrification: Nylon 46 in start/stop and e-motor components, TPC in HV cables - System Cost optimization: High Flow PA6 in various components, TPC in Brake Tubes - Improved LCA: biobased materials as PA410 and TPC-Eco Typical Application Solutions concern: air induction systems, engine and transmission components, electrical systems, structural&safety parts.
Video

Monitoring the Progression of Micro-Pitting in Spur Geared Transmission Systems Using Online Health Monitoring Techniques

2012-03-16
Micro-pitting is a fatigue effect that occurs in geared transmission systems due to high contact stress, and monitoring its progression is vital to prevent the eventual failure of the tooth flank. Parameter signature analysis has been successfully used to monitor bending fatigue failure and advanced phases of gear surface fatigue failure such as macro-pitting and scuffing. However, due to modern improvements in steel production the main cause of gear contact fatigue failure can be attributed to surface micro-pitting rather than sub-surface phenomena. Responding to the consequent demand to detect and monitor the progression of micro-pitting, this study experimentally evaluated the development of micro-pitting in spur gears using vibration and oil debris analysis. The paper presents the development of an online health monitoring system for use with back-to-back gear test rigs.
Video

Hybrid Cost Assessment Plus AMT/Hybrid Concept

2012-03-27
The automotive industry continues to develop new powertrain technologies aimed at reducing overall vehicle level fuel consumption. This paper discusses the development of a new highly efficient parallel hybrid transmission for use in transversely installed powertrains for FWD applications. FEV is developing a new 7-speed hybrid transmission for transverse installation. The transmission with a design torque of 320 Nm is based on AMT (automated manual transmission) technology and uses a single electric motor. The innovative gearset layout combines the advantages of modern AMTs such as best efficiency, low costs and few components (reduced part count) with full hybrid capabilities and electric torque support during all gear shifts. Furthermore, the gear set layout allows for very short shift-times due to the favorable distribution of inertias. Other features include an A/C compressor being electrically driven by the electric motor of the transmission during engine start/stop phases.
Technical Paper

Simultaneous Inspection and Correction of Gears in Production

1928-01-01
280062
BY means of the gear-correcting process described, spur and helical gears are corrected to give a high degree of uniformity in spacing and profile so that the gears become practically interchangeable. They acquire a “crown face” which enables them to run with unusual quietness under practical conditions. This is essentially an inspection-correction process, as it automatically finds and eliminates the errors. The lap is the important item in the process. It is of chilled cast-iron, gray cast-iron, or type metal, and is made by casting in a mold around a steel chill cut to approximate the gear to be corrected but has a face-width several times that of the gear. The lap, when completed, looks like a wide-faced internal gear.
Technical Paper

Ground Gears and Transmission Design

1928-01-01
280061
GROUND teeth for transmission gears are advocated because they can be made to the same degree of accuracy as the other fine working-parts of a motor-car. The designing engineer is held responsible for conditions unfavorable to the adoption of gear grinding by the production department. Mr. Orcutt believes that cluster gears should be avoided because it is impossible to finish them accurately. Fundamental principles of rigid shafts and correct bearing arrangements are laid down, and the degree of accuracy is specified for the fitting parts. Transmission-case design still needs development and study to avoid resonance. Designs are recommended that will provide ample center distance to avoid pinions with a small number of teeth. The unmodified involute is recommended as the most satisfactory form of tooth. Spigot bearings receive special consideration. Two designs of transmission are submitted, in one of which the spigot bearing is eliminated.
Technical Paper

Aircraft Propellers

1929-01-01
290059
NEARLY all the aircraft propellers used by both the Army and the Navy are of the detachable-blade type. The Navy has found it necessary to make its own designs and to furnish the propeller manufacturers with finished detail drawings. The author lists the sources from which data can be obtained and shows a chart from which can be found a diameter and setting of a pair of detachable blades that will give reasonably good performance for nearly any horsepower, revolutions per minute and airspeed commonly used with the direct-drive type of propeller. Discrepancies between model tests and wind-tunnel tests are cited, and the author then considers the subject theoretically. Substitute propellers are next considered, and also the strength of propellers.
Technical Paper

Gearing of Aircraft Propellers

1929-01-01
290062
FOLLOWING a brief outline of the development of aircraft propellers and a statement of the most important fundamentals of propeller design, the authors discuss the problem of propellers for use on geared-down engines, this being the installation of reduction gearing between the crankshaft of the engine and the propeller hub when the increase of airplane-performance characteristics more than offsets the added complication of the installation. The advantages and the disadvantages of using reduction gearing are considered. Concerning the installation of reduction gears, the authors state that the decision whether to use gears or not must result from a compromise between the gains and the losses involved and the amount of net gain depends largely upon the particular engine and airplane combination and its designed performance.
Technical Paper

Quieter Gears Are Being Demanded! How Shall We Make Them?

1933-01-01
330019
LIMITATIONS of present processes for cutting and finishing transmission gears are covered in a general way by Mr. Cederleaf. He shows also that future demands for more quiet transmissions can be met only by an equal improvement in gear-cutting-and-finishing equipment; or by the development of new processes; or by the realization, on the part of engineers, that the most economical method of obtaining better results is, by redesign, to eliminate from the transmission the necessity for greater dimensional accuracy.
Technical Paper

Independent Wheel Suspension

1933-01-01
330029
THE study of composite front axles, called fallaciously “independent wheels,” deals with the accelerations due to the inequalities of the road surface and with the resonance of the car caused by the vibrations thus produced. This study cannot be treated separately but must be taken as part of the complete problem of the resonance of the whole car to the road, according to Mr. Broulhiet. Extensive experiments have confirmed that vertical suspension, road-holding qualities, coachwork resonance and the resonance of the steering gear are all interdependent. Therefore, the problem of road resonance must be dealt with as a whole, if one wishes to grasp the problem in its complexity and have that scientific backing necessary for rapid progress in the mind of the designer. Mr. Broulhiet outlines, from personal research in this field, four basic conditions to obtain the best results. The geometry and equilibrium conditions of proposed mechanical realizations are analyzed.
Technical Paper

The Properties and Selection of Automotive Steels

1932-01-01
320057
METALLURGISTS must supply engineers with data on the physical properties of steels so that the skill of both can be used, particularly for machinery in which light weight is essential. The engineer who has not a metallurgical department at his command cannot be sure of duplicating results claimed by steel makers, and the physical-property data that have been given in the S.A.E. HANDBOOK are based on minimum results, for safety. More complete information as to what actually can be expected is desirable, and a subcommittee has had a large number of tests made on identical samples from several heats of two alloy steels. The results for these two steels have been coordinated in probability curves that were developed with the aid of frequency charts. Some steels are not uniform in their physical properties in large sections. The author presents suggestions for steels that are suitable for large sections, with the strengths that can be expected from them.
Technical Paper

Fundamentals of Automotive Lubrication

1932-01-01
320058
SATISFACTORY performance of a lubricant depends upon characteristics of the lubricant, operating conditions and design of the device in which the lubricant is used. Applied lubrication requires a study of the relation among these factors in their effect upon performance. The authors treat journal bearings, ball and roller bearings and gears. Equations are given for journal bearings operating under various conditions of design, lubrication, friction and heat dissipation. The authors conclude that neither ZN/P nor PV alone is adequate as a measure of the power dissipated by a bearing, a composite relation involving both terms being required over a large part of the operating range. They show that each bearing has a minimum value of ZN/P below which it may get into the unstable region of thin-film lubrication and fail.
Technical Paper

Carbureter Design for the C. F. R. Detonation Engine

1931-01-01
310020
ACCURACY of metering and speed in manipulation are the two prime requisites in a carbureter for detonation-measurement work, according to the author, who outlines briefly the development, for use with the Cooperative Fuel-Research Committee test engine, of an instrument based upon the Dobbs carbureter designed by the Anglo-Persian Oil Co. for detonation testing. As now manufactured for routine testing, the device consists of four float-bowls having entirely seperate air and fuel channels, the channels from each bowl being controlled by individual air and fuel valves that operate in unison. The throttle, which is of the barrel type, is operated by a worm and gear and has an indicator arm attached to facilitate duplication of throttle settings. Results of tests indicate that this carbureter is satisfactory over a range from 40 deg. fahr. to the point at which gassing of the fuel becomes objectionable. Special nozzles can be provided for fuel densities outside the normal range.
Technical Paper

SPUR-GEAR GRINDING AND TESTING 1

1923-01-01
230050
A grinding-machine for finishing spur-gears is illustrated and described; claims are made that it will grind transmission gears on a production basis after they have been heat-treated and will produce correct tooth-contour, smooth finish and accurate tooth-spacing, these features being necessary in producing gears that are interchangeable and that run quietly. This machine is of the generating type, its action being that of rolling a gear along an imaginary rack and using the grinding wheel as one tooth of the rack. The dished grinding-wheel is reversible, 30 in. in diameter, mounted below the gear, and can be swiveled to the right or left of the center position up to an angle of 25 deg. The work-spindle carries the indexing and the generating mechanisms at the rear, where they are accessible and yet are protected.
Technical Paper

THE PACKARD SINGLE-EIGHT

1923-01-01
230039
Stating the fundamental characteristics of the modern motor-car under the headings of performance, safety, economy, comfort and taste, the authors define these terms and discuss each basic group. The specifications of the car in which the single-eight engine is installed are given, and the reasons governing the decision to use an eight-cylinder-in-line engine are enumerated. Following a somewhat lengthy discussion of the components of engine performance, the design of the engine is given detailed consideration under its divisions of crankshaft design and the methods employed, gas distribution, the operation of the fuelizer, cylinders, valve gear and the arrangement of the accessories. Transmission design and the wearing quality of gears receive similar treatment.
Technical Paper

GEAR GRINDING1

1923-01-01
230018
The author discusses only gear-grinding work on gear teeth subsequent to heat-treatment and pays particular attention to automobile transmission gears. He states that as yet very little is being done in the grinding of gear teeth that have not been heat-treated. The salvaging of gears that have been rejected and the finish-grinding of gears that have grinding stock remaining upon the teeth are commented upon, together with remarks on the cost of grinding, the history of gear grinding, the different classes of work performed, gear-grinding machines in general, tooth-form and gear wear. It is stated that gear grinding is commercially a production operation having as its aim the placing of the correct tooth-shape and proper surface-finish on gear teeth so that the gears can move accurately, noiselessly and without wear; and that the cost of finished acceptable transmissions is less than when the process of finish-grinding is used.
Technical Paper

HOW TO USE GEAR-CUTTING HOBS

1923-01-01
230020
Detroit Section Paper - Since a gear is a product of the cutting tool, the gear-cutting machine and the operator, it can be no more accurate than the combined accuracy of these fundamental factors. All gear manufacturers aim to eliminate split bearings, high and low bearings, flats and other inaccuracies in tooth contour, because a gear having teeth the contours of which comply with the geometrical laws underlying its construction is by far the most satisfactory. Illustrations are presented to convey an understanding of the geometrical principles involved, together with other illustrations of testing instruments and comments thereon. The application of these instruments is termed quality control, which is discussed in some detail under the headings of hob control, machine control and gear control.
Technical Paper

THE AUTOMOTIVE AIRBRAKE-WHY AND HOW

1925-01-01
250013
In an endeavor to find an engineering justification for the use of the airbrake on automotive vehicles, an investigation was first made as to what actually causes a car to stop when the brakes are applied; and it was ascertained that nothing that can take place within the car itself can directly influence the motion of the automobile as a unit, that its motion can be changed only by some force external to the car itself. Four such forces are normally present, namely, wind resistance, road resistence, gravity, and the adhesion of the road to the wheels. The first two are negligible. Grades have a measurable effect on the stopping distance, but the force that actually stops the car is the last named: the force that is applied from a point external to and in a direction opposite to that of the motion of the automobile.
Technical Paper

A GRAPHICAL DETERMINATION OF CHANGE SPEED GEAR BEARING LOADS

1910-01-01
100001
The question of the selection of the proper sizes of ball-bearings for any given set of conditions is one that should properly receive the consideration of those most expert in their design and application. However, in change speed gear design, where the ratio between the diameters of the bearings and the diameters of the gears is small, the sizes of the bearings have so great an influence on the center distance of the shafts and the shape and outline of the casing that a change in the bearings from those originally laid out frequently necessitates the redesigning of the whole job.
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