Next-generation Fuel-efficient Automated Manual Transmission

Abstract

OVERVIEW: Fuel efficiency standards on vehicles are becoming increasingly strict to curb global warming, and Japan and Europe plan to reduce current standard values by about 25% in the timeframe from 2008 to 20101). Transmission manufacturers have responded with a range of proposals for enhancing fuel efficiency. A number of alternative schemes have been developed as a more fuel-efficient next-generation transmission to succeed the existing ATs (automatic transmissions) and CVTs (continuously variable transmissions). One approach that is attracting considerable interest is an AMT (automated manual transmission), essentially an MT (manual transmission) with an automated control system. Hitachi Group is now developing a unique torque-assist AMT that is compactly implemented by adding a friction clutch mechanism to a conventional AT. Combining the fuel efficiency of an MT with the seamless shifting of an MT, this approach shows excellent promise as a compact and cost-effective next-generation transmission. Hiroshi Kuroiwa Naoyuki Ozaki Takashi Okada Masaru Yamasaki