Off-highway CVTs

OFHOCT03_01

10/01/2003

Abstract
Content

A continuously variable transmission can improve the fuel efficiency of heavy-duty diesels by matching the engine's torque/speed to the applied load through the smooth torque multiplication of the transmission.

The need for significant fuel-economy improvements in off-highway vehicles has never been greater than it will be over the coming years, according to researchers at the Southwest Research Institute (SwRI). In a conventional vehicle, the engine is responsible for meeting most of the requirements for varying vehicle speed and acceleration, while the transmission intermittently shifts between fixed ratios. Most vehicle speed variation therefore results in internal-combustion (IC) engine speed variation.

Heavy-duty vehicles, with lower-speed engines, compensate for the lack of engine speed range with a greater number of fixed transmission ratios. Although the speed-varying capabilities of IC engines vary widely, they all share a common trait in that their regions of best brake specific fuel consumption (BSFC) comprise a relatively small portion of their overall operational envelope.

Meta TagsAdditional Details
Publisher
Published
Oct 1, 2003
Product Code
OFHOCT03_01
Content Type
Magazine Article
Language
English