Browse Topic: Overdrive transmissions

Items (23)

Domestic Performance Torque Converter Manufacturing

J2440_201910 (Current)10/09/2019

The scope of this SAE Draft Technical Report is to establish dimensional standards for high-performance domestic torque converter manufacturers. Many torque converter manufacturers build converters to their own standards. Some of these standards may be outside of the specifications that define a quality performance torque converter.

Motor Vehicle Council

Comparison of Dynamic Performance and Fuel Consumption of Direct-drive and Overdrive Transmission Tractors

2016-01-801909/27/2016

The main objective of this project was to compare the fuel consumption and dynamic performances of direct-drive and overdrive transmission tractors. Fuel consumption was evaluated at constant high speed and on various road profiles, while the dynamic performance was assessed on various road profiles only. The SAE Fuel Consumption Test Procedure (J1526) was used for constant high speed fuel consumption track test evaluations. The direct-drive transmission tractor consumed less than the overdrive transmission tractor, even though it was heavier. The testing on various road profiles was conducted using a towing dynamometer, for comparing the dynamic capability of the tractors when simulating the same towing load on two hilly road profiles: the Townes Pass path (in the Rocky Mountains) and the Saguenay path (in the Saguenay region of Quebec). Each tractor was to haul the set load along the given path while trying to attain 90 km/h speed. Results from the test showed almost identical

Surcel, Marius-Dorin, Bonsi, Adime Kofi

Big losers

11AEID0419_0104/19/2011

Heavy trucks increasingly employ lighter-weight materials and sleeker shapes-not just for body but major chassis components as well-to trim fuel consumption and emissions. It should come as no big surprise that the “heavy hitter” in boosting heavy-vehicle fuel efficiency is the hybrid powertrain, be it the electric or hydraulic variety. But, as many industry experts will tell you, hybridization does not benefit all medium- and heavy-duty vehicles equally. “There are technologies out there today and expected in the next five years that can help achieve what the president [Barack Obama] said was a 25% fuel-consumption reduction. That's his aim; I think it's achievable,” said Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corp. These technologies include hybrid powertrains, clean diesel technology, improved aerodynamics, low rolling resistance tires, and lightweight designs.

Gehm, Ryan

Automotive Transmission Terminology

J645_200903 (Historical)

03/03/2009

The following listed definitions are intended to establish terminology and criteria for describing the various kinds of automotive transmissions. A specific arrangement may be described by a combination of several of these definitions.

Automatic Transmission and Transaxle Committee

Automatic Transmissions—Manual Control Sequence

J915_200710 (Historical)

10/22/2007

The scope and purpose of this SAE Recommended Practice is to provide a standard pattern or sequence for the manual control of automatic transmissions in passenger cars and light-duty trucks. This generally refers to left hand drive mechanical shift applications.

Automatic Transmission and Transaxle Committee

Fuel Consumption and Energy Balance of “Optimized CVT-Hybrid-Driveline”

2006-01-325910/16/2006

Nowadays the task to diminish energy consumption and air pollution caused by road traffic occupies a key issue. One of several approaches is the hybrid driveline technology. At the Technical University Munich through a research project the “Optimized CVT-Hybrid-Powertrain” was designed and manufactured and is under investigation. This research project is run in close cooperation between university and industry (EPCOS AG, GM Powertrain Europe, ZF Friedrichshafen AG and ZF SACHS AG). The project is focused on reduction of fuel consumption at low additional cost for hybridization. The “Optimised CVT-Hybrid-Powertrain” is a full hybrid car driveline using Diesel-engine, electric motor with double layer capacitors for electric energy storage and a CVT-type transmission. Vehicle pull away is typically done by electric driving; the ic-engine is started by a fast ratio change of the CVT-transmission without additional starter. The driveline is assembled into an OPEL VECTRA vehicle for

Höhn, Bernd-Robert, Pflaum, Hermann, Tomic, Daniel

Pushbelt CVT Efficiency Improvement Potential of Servo-electromechanical Actuation and Slip Control

2004-40-004908/23/2004

By using the ability to shift to high overdrive ratios, a CVT equipped vehicle can outperform the fuel economy of its counterpart with conventional automatic transmission. A further signi cant reduction of fuel consumption can be obtained by reducing transmission power loss. The main sources of power loss are well known to be losses inside the V-belt variator and losses caused by driving the hydraulic pump. Signi - cant reduction of these losses will increase the attractiveness of the V-belt type CVT. This paper rst analyses the most important loss contributions present in a reference transmission and how they depend on actuation and control properties, like pump driving power, over-clamping and variator slip. Based on this analysis, actuation and control improvements will be proposed. The effciency increase is presented, that can be expected when the hydraulic pump is replaced by a servo-electromechanical actuation system, and when variator slip control is introduced. The effciency

Veenhuizen, P. A., Bonsen, B., Klaassen, T.W.G.L., Albers, P.H.W.M., Changenet, C., Poncy, S.

Dynamic Performance Analysis of a Full Toroidal IVT A Theoretical Approach

2004-40-003008/23/2004

The torque controlled full toroidal IVT (Infinitely Variable Transmission) provides significant fuel economy benefit over conventional stepped ratio transmissions. This is achieved, in part, by using high overdrive ratios. This benefit must be provided alongside good driveability, which requires the system to have a fast response while being well damped. This paper gives a theoretical overview of the dynamic response of the IVT focusing on different interactions between the full toroidal variator and hydraulic control circuits. The concept of system stability is applied to sub-systems and their interactions to indicate design requirements of this torque controlled transmission.

Fuchs, Robert, Hasuda, Yasuhiko, James, Iain

Development and Introduction of Chrysler's New Automatic Transmission Fluid

98267410/19/1998

Chrysler began a limited development program directed toward a new automatic transmission fluid (ATF) early in 1989 and launched a full time effort in 1994. The development process for the new ATF involved a significant level of bench testing and eventually vehicle tests to evaluate the durability and shift quality of the ATF. The bench tests included those that pertain to oxidation and shear stability, anti-wear, frictional properties and torque converter shudder. Vehicle tests were primarily extended durability in both internal vehicle fleets and at external taxi sites. The mileage accumulated in this phase of the development program exceeded two million miles, all with no fluid drains out to 100,000 miles. Additionally, shift feel tests were conducted in Chrysler vehicles to verify compliance to targets. This paper summarizes the tests and results that lead to the development of the new Chrysler fill-for-life automatic transmission fluid.

Sumiejski, James L., Florkowski, Dennis W., King, Tracey E., Skrobul, Anthony P.

Domestic Performance Torque Converter Manufacturing

J2440_199802-TEST-REC (Historical)02/01/1998

Motor Vehicle Council

Domestic Performance Torque Converter Manufacturing

J2440_199802 (Historical)

02/01/1998

Motor Vehicle Council

A Methodology for Enumeration of Clutching Sequences Associated with Epicyclic-Type Automatic Transmission Mechanisms

96071902/01/1996

This paper presents a systematic methodology for the enumeration of clutching sequences associated with epicyclic-gear-type automatic transmission mechanisms. The methodology is based on the concept that an epicyclic gear mechanism can be decomposed into several fundamental geared entities and that the overall speed ratio of an epicyclic gear mechanism can be symbolically expressed in terms of its fundamental geared entities. First, a procedure for estimating the overall speed ratio of an epicyclic gear mechanism, without specifying the exact gear dimensions, is outlined. Then, an algorithm for comparing various possible speed ratios of an epicyclic gear mechanism is described. Finally, a methodology for systematically enumerating all possible clutching sequences of an epicyclic gear mechanism is established.

Hsieh, Hsin-I, Tsai, Lung-Wen

Results of a 500,000-Mile Field Test of a Gear Lubricant and an Engine Lubricant in Heavy-Duty Manual Transmissions

91240810/01/1991

A GL-5 gear lubricant containing a dispersed solid borate additive and a CD synthetic engine lubricant were evaluated in the overdrive transmissions of 17 new Class 8 trucks in a 500,000-mile per truck, on-highway field test. With 500,000-mile oil drain intervals, both lubricants gave acceptable performance as judged by end-of-test inspections: deposit/sludge formation was minimal, overall wear was low, and seal/yoke performance was good. The borate lubricant gave a statistically significant lower wear rate than the synthetic lubricant based upon oil sample analysis; inspections also showed lower wear on some parts. Additionally, oil sample analysis from the tandem drive axles showed that the forward axle gave a statistically significant higher wear rate than the rear axle. Transmission and drive axle oil temperatures were monitored during a portion of the test.

Salentine, C. G.

The Development of Hydrodynamic Transmission for Chinese City Bus

89253311/01/1989

A SRM* type torque converter and power shift gear box were designed and trial-produced for Chinese city bus, considering the cost of manufacture as the first factor. The SRM type torque converter used in this transmission was independently developed and tested in China with very good results. The combination of SRM torque converter with lock-up clutch and two forward speeds including one overdrive speed has made the Chinese city bus perform better in fuel economy, gradeability, ease of handling and in start quality than the conventional mechanical gear box.

Luo, Bangjie, Ma, Wenxing, Wu, Shurong

The Potential And Advantages Of Continuously Variable Transmissions For Automotive Applications

885063

09/01/1988

The theoretical advantages of continuously variable transmissions (CVT) in vehicles can only be realized in practice if new design approaches are taken as a basis. The possible fuel savings and reduction of pollutants require transmissions with a wide overdrive gear ratio spread. The combination of gears and CVT is the only way of achieving the necessary gear ratio spread. The paper introduces a new modular design system embracing both the new manual transmission for the future and the new CVT. This new design system makes it possible to produce both transmission versions economically on one production line.

Höhn, B.-R.