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Technical Paper

• Oxidation Stability • Shear Stability • Rubber Swell Properties of Automatic Transmission Fluids

A NEW TEST is described for studying the oxidation stability of automatic transmission fluids (ATF). The test shows an excellent correlation with transmission oxidation tests and points out the importance of time as a variable in such studies. Carefully controlled automobile dynamometer tests have been used to study the shear stability of ATF's. Data are presented showing a comparison of driving conditions, transmissions, and V.I. improvers on shear stability. Results are related to the 50-hr Hydra-Matic durability test. The poor reproducibility of rubber swell measurements on commercial transmission seals is due largely to differences in the rubber compounds. A great improvement in the reproducibility may be made by taking into account the specific gravity of the rubber sample.*
Technical Paper

“Transet” Transmission Controller Development System

A program was developed that provides a user friendly interface for developing and testing shift tables in a powershift transmission. This program is Windows based and runs on an IBM compatible P.C. When coupled with a suitable controller, transmission designers have a useful tool for the development of transmission shift timing. The system is designed to be used in an engine test cell or for actual vehicle tests. This allows the vehicle operator to call up and edit shifts on a P.C. screen and then drive the vehicle using the new shifts. This allows the operator to evaluate results of real time shifts immediately.
Technical Paper

“The Producers” New Row-Crop Tractors From John Deere

A line of five new row-crop tractors is being introduced by John Deere with innovative features including a 15-speed full power shift transmission, a high capacity, highly-maneuverable full-time mechanical front-wheel drive and micro-processor controlled instrumentation. In addition, the tractors have increased power, improved fuel economy, greater hydraulic power, improved hitch sensing, improved operator controls, lower sound levels, and revised styling. This paper documents the design and development of these new John Deere row-crop tractors.
Technical Paper

“GoldDrive”-Infinite Variable Drive Consisting of Fixed Displacement Pumps & Motors

1 “GoldDrive” is an infinite variable, bi-directional drive consisting of hydraulic fixed displacement pumps and motors. As a matter of fact “GoldDrive” is the hydraulic equivalent of the mechanical differential. The idea behind the development of “GoldDrive” is to overcome the limitation of starting torque. According to the traditional equation, torque is equal to power over speed and as a result, we need an infinite amount of torque to start a load at zero output speed. The solution is Slippage, slippage of electrical, mechanical, hydraulic and pneumatic transmissions. “GoldDrive” enables us to achieve maximum efficiency and starting torque at zero output speed without slippage.
Technical Paper

the effects of … Machine and Foundation Resilience and of Wave Propagation on the Isolation Provided by Vibration Mounts

THE effects on the transmission of vibration through isolation mounts of machine and foundation resilience, and of wave propagation are investigated. The prediction of the effectiveness of mounts is discussed, and curves are presented for estimating their effectiveness under certain conditions. A number of conclusions are drawn relevant to the problems of mount design and selection.
Technical Paper

eFlite Dedicated Hybrid Transmission for Chrysler Pacifica

Electrified powertrains will play a growing role in meeting global fuel consumption and CO2 requirements. In support of this, FCA US has developed its first dedicated hybrid transmission (the eFlite® transmission), used in the Chrysler Pacifica Hybrid. The Chrysler Pacifica is the industry’s first electrified minivan. [2] The new eFlite hybrid transmission architecture optimizes performance, fuel economy, mass, packaging and NVH. The transmission is an electrically variable FWD transaxle with an input split configuration and incorporates two electric motors, both capable of driving in EV mode. The lubrication and cooling system makes use of two pumps, one electrically operated and one mechanically driven. The Chrysler Pacifica has a 16kWh lithium ion battery and a 3.6-liter Pentastar® engine which offers total system power of 260 hp with 84 MPGe, 33 miles of all electric range and 566 miles total driving range. [2] This paper’s focus is on the eFlite transmission.
Technical Paper

e-Thermal: A Vehicle-Level HVAC/PTC Simulation Tool

This paper describes a vehicle-level simulation model for climate control and powertrain cooling developed and currently utilized at GM. The tool was developed in response to GM's need to speed vehicle development for HVAC and powertrain cooling to meet world-class program execution timing (18 to 24 month vehicle development cycles). At the same time the simulation tool had to complement GM's strategy to move additional engineering responsibility to its HVAC suppliers. This simulation tool called “e-Thermal” was quickly developed and currently is in widespread (global) use across GM. This paper describes GM's objectives and requirements for developing e-Thermal. The structure of the tool and the capabilities of the simulation tool modules (refrigeration, front end airflow, passenger compartment, engine, transmission, Interior air handling …) is introduced. Model data requirements and GM's strategy for acquiring component data are also described.
Technical Paper

Zoonoses and Enclosed Environments

The likelihood of transmission of potential disease agents between animals and man during spaceflight is a real concern. Development of disease exclusion lists for animals and refinement of animal containment units have been the principal means of providing protection to the crew members. Awareness of potential latent infections and a judicious use of the higher risk category of animals such as wild-caught nonhuman primates provides another level of protection. Use of high efficiency filters, gasketing, and differential air pressures have all enabled increasing levels of safety through containment of potential aerosol escape from animal habitats.
Technical Paper

Zeroshift. A Seamless Automated Manual Transmission (AMT)With No Torque Interrupt

Zeroshift technology allows a manual transmission to change gear in zero time. The Zeroshift automated manual transmission (AMT) is easy to manufacture and allows a cost effective alternative to the traditional torque converter based automatic transmission. Zeroshift offers potential fuel economy improvements from driveline efficiency and the best possible vehicle acceleration. Compared to an existing AMT, Zeroshift offers an uninterrupted torque path from the engine to vehicle which allows for a seamless gearshift. This paper provides an introduction to the technology together with test data from a demonstrator vehicle.
Technical Paper

Zeroshift Automated Manual Transmission (AMT)

Zeroshift technology allows a manual transmission to change gear in zero seconds. The Zeroshift Automated Manual Transmission (AMT) is easy to manufacture and allows a cost effective alternative to the traditional torque converter based automatic transmission. Zeroshift offers potential fuel economy improvements from driveline efficiency and the best possible vehicle acceleration. Compared to an existing AMT, Zeroshift offers an uninterrupted torque path from the engine to vehicle which allows for a seamless gearshift. This seminal paper provides an introduction to the technology together with test data from a demonstrator vehicle.
Journal Article

ZF New 8-speed Automatic Transmission 8HP70 - Basic Design and Hybridization-

The world's first six-speed automatic transmission for passenger cars was introduced to the market by ZF in 2001. The 6HP-family is based on a Lepelletier planetary gear set. An advanced version of these transmissions was launched in 2006. The 2nd generation offers significantly improved customer-relevant features such as reduced fuel consumption, response time and shifting speed. With regard to the increasing requirements especially in reduction of CO2 emissions, a new eight-speed transmission is now under development. The main targets for this transmission family are a further significant reduction in fuel consumption and emissions, good driving performance and state of the art driving comfort. The paper describes the transmission 8HP70, the schematic, main features and major design components. Key figures like transmission weight and size, fuel efficiency benefits and driving performance are shown compared to the 6-speed transmission of the 2nd generation.
Technical Paper

ZF EcoLife - The latest Generation of Powershift Automatics for Transit Buses

The megatrends "reduction of emissions" and "fuel consumption reduction" play a predominant role in the development of powertrains. For transit buses this implies both the reduction of emissions and pollutions of the internal combustion engine, and, on the other hand, a further reduction of noise and brake dust. Also very important is the reduction of both fuel consumption and CO₂ emissions. For all these targets the actual developments on the engine side have led to great improvements in the last decades, but what can be mentioned for the other components of the powertrain, especially looking for transmissions? First of all the relevant trends for transit buses have to be considered: A large increase of the torque of the combustion engines during the last years has a big impact on the development of transmissions for buses.
Technical Paper

ZF 6-Speed Automatic Transmission for Passenger Cars

With the introduction of the ZF “myTronic6” (6 HP 26) in 2001, the Division Car Driveline Technology of the ZF Friedrichshafen AG has developed and introduced a new 6 speed stepped automatic transmission for passenger cars. This paper describes the gear set concept, the mechanical design and specific functions of this transmission. The 6 HP 26 is part of the new 6- speed program which comprises 3 transmission types. It will replace the existing ZF 5 speed program completely within the next years.
Technical Paper

ZF 5-Speed Transmissions for Passenger Cars

With the introduction of the 5HP24 in early 1996, ZF has completed their product line for 5-speed transmissions. This transmission was especially developed for 8 cylinder engines and has achieved important improvements in fuel consumption, performance, comfort and reliability. This report shows, that 5-speed automatic transmissions result in a reduced fuel consumption, even in countries with speed limits. For example the 5HP24 incorporates the latest developments such as: converter wirth controlled slip clutch (CSC) measures to allow engine speed between 600 and 7200 rpm modern closed loop control shifting strategy performance improved Transmission Control Unit (TCU)
Technical Paper

Xtend: a New Concept for Automatic Wear Compensation in Clutches

With the Xtend clutch a new concept for automatic wear compensation, which is suitable for push- and pull-type clutches of all sizes, has been developed. A very high level of accuracy of the adjusting process could be achieved under all operating conditions by the direct mechanical coupling to the wear of the clutch facings. It can be used without any changes to existing interfaces and possesses the same robustness and is as easy to handle as any conventional clutch.
Technical Paper

Worldwide Automotive Powertrain Directions

Using the overall efficiency obtained with today’s automotive power plants on the U.S. Metro Route as a baseline for comparison purposes, this paper reviews the major efficiency opportunities available in the next decade for a wide variety of automotive engine candidates. The impact of a variety of alternate fuels on candidate engine thermal efficiency is also presented. A family of continuously variable transmissions, having different levels of efficiency, are then used to project the overall efficiency of these engine candidates and fuels on the U.S. Metro Route in the 1990+ time frame. The direction of engine design, material and control trends during this time interval are also discussed.
Technical Paper

World Transmissions for the 1990 Truck Market

A new line of on-highway transmissions has been designed and developed by Allison Transmission Division. This new product line, identified as the World Transmission Series (WT), has been designed with emphasis on cost-effectiveness, greater integration with vehicle systems and advanced technology to meet market demands into the 21st century. New design concepts both in power train component arrangement and electronic controls have been coupled utilizing concurrent engineering and systems engineering principles. The result is a customer-driven product line which, when produced by Allison, will exceed world class standards of quality, performance and value.
Technical Paper

Wireless Transmission of Electric Energy

This article focuses on the wireless transfer of energy. It describes the operation of a transformer without magnetic circuit associated with a resonant inverter to meet the constraints imposed by mobile sources (catenaries with magnetic induction to power electric vehicles). The receiving and transmitting units consist of an air-gap transformer and a generator who feeds the transformer. In this article, we show how to determine the transformer's parameters and configuration needed for this transfer to be efficient. The transformer is fed by a half-bridge converter for serial resonant load. The primary winding of the transformer is fixed on the ground. The secondary winding can move horizontally in a parallel plane of that of the primary. This application targets mainly the transfer of static electricity for the charging of batteries and super capacitors in electric cars and trams.
Technical Paper

Wireless Power Transmission: Applications and Technology Status

The opportunity for the application of Wireless Power Transmission (WPT) technologies is growing. Applications covering terrestrial, airborne and space missions are evolving. Concepts for terrestrial systems for powering remotely located regions by the use of renewable energy sources; airborne systems used for remote observation, communication relay, and environmental monitoring; and space based systems for potentially powering the elements of a space infrastructure are being developed. This paper will present the history of wireless power transmission systems and summarize current and future applications and technology. Design constraints for terrestrial systems, airborne platforms and space systems will be presented.
Journal Article

Wiper System Dynamic Forces: from the Test Bench to the Vehicle

Acoustic comfort inside the vehicle is required whenever a wiper system is in function: front wiper motor noise is of great influence on the global comfort and its perception inside the car is 100% due to transmission of vibrations through wiper system fixation points on the vehicle. As any active source, both car manufacturer and system supplier need to be involved, at early stages of project development, in order to master the vibroacoustic integration of the system into the vehicle. This paper presents an experimental methodology dedicated to the front wiper system that offers the possibility to estimate the acoustic comfort inside the vehicle during project deployment phase, when modifications can still be proposed. Based on the XP-R-19701 standard, the procedure allows to measure, on a bench, the dynamic forces transmitted via the fixation points and details how to transpose them to the vehicle, taking into account the different specificities of the wiper system.