Wet friction materials for continuous slip torque converter clutch – Fuel economy improvement of passenger cars equipped with automatic transmission –

Author(s):  
Y. Kamada ◽  
N. Wang ◽  
T. Kotanigawa ◽  
J. Kawabata ◽  
M. Araki ◽  
...  
Author(s):  
Chunhao J. Lee ◽  
Kumar Hebbale ◽  
Shushan Bai ◽  
Farzad Samie

Friction Launch transmissions use a wet multi-plate clutch to replace the torque converter in an automatic transmission. The main benefit of this technology is fuel economy improvement as a result of eliminating the losses in the torque converter. By using one of the range clutches inside the transmission instead of an input clutch in place of the converter, the benefits of this integrated friction launch technology, such as reduction in mass, packaging, and cost, can be enhanced. The availability of new automatic transmissions with higher number of speeds and wider overall ratio spreads makes this technology more viable than ever before. This project focuses on control issues with the friction launch clutch which include developing robust control algorithms for launch and creep, and providing damping to the driveline, when required, and ensuring acceptable vehicle drivability. This paper describes in detail the development of vehicle launch control algorithms. Vehicle test data is presented to show that the control strategy developed in this project significantly reduces the gap between the drivability of a starting clutch vehicle and a torque converter equipped vehicle.


Author(s):  
Y. Gene Liao ◽  
Chih-Ping Yeh ◽  
Allen M. Quail

The impact of the vehicle fuel economy in tactical convey is amplified due to the fact that much of the present logistics support is devoted to moving fuel. Fuel economy improvement on medium-duty tactical truck has and continues to be a significant initiative for the U. S. Army. The focus of this study is the investigation and analysis of Automated Manual Transmissions (AMT) that have potential to improve the fuel economy of the 2.5-ton cargo trucks. The current platform uses a seven-speed automatic transmission. This study utilized a combination of on-road experimental vehicle data and analytical vehicle model and simulation. This paper presented the results of (1) establishment of a validated, high fidelity baseline analytical vehicle model, (2) modeling and simulation of two AMTs and their control strategy, and (3) optimization of transmissions shift schedules to minimize the fuel consumption. The fuel economy discrepancy between experimental average and the baseline simulation result was 2.87%. The simulation results indicated a 12.2% and 14.5% fuel economy improvement for the 12-speed and 10-speed AMT respectively.


Author(s):  
E. M. Evans ◽  
J. Whittle

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.


2001 ◽  
Author(s):  
Thomas DeMurry ◽  
Yanying Wang

Abstract The primary objectives of this study are (1) to validate the hardware design and control methodologies for preserving the thermo-mechanical integrity of a launch clutch emulating a torque converter and (2) to develop a simple, control oriented clutch-temperature model that may act as a virtual thermocouple in the processor of an automobile for real-time clutch-temperature predictions. In a dynamometer test cell, a Ford CD4E transaxle is instrumented with a thermocouple-based telemetry system to investigate clutch thermal characteristics during engagements, neutral idle, single and repeated launching, torsional isolation, and hill holding. A nonlinear, SIMULINK™-based model for estimating temperature is developed. The results from the simulations are in good agreement with the experimental data.


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