Abstract
KEYWORDS
ZF-Automatic transmission, 6-speed transmission, product range, fuel efficiency, environmental protection
ABSTRACT
With ZF’s introduction of the first 6-speed automatic transmission for rear-wheel driven passenger cars in 2001, a large step was taken towards fuel efficiency improvements and environmental protection in the automatic transmission sector. When compared with former 5-speed transmissions, the new 6-speed generation makes fuel savings of at least 5% possible. In addition to the new gear set, functionalities such as low viscosity oil and the extended use of the slipcontrolled lock-up clutch have been developed. The new 6-speed transmissions are 10 to 15% lighter and are smaller than comparable 5-speed transmissions. Developments have enabled the number of transmission parts to be reduced by 30%. By integrating the TCU into a Mechatronics module within the transmission, it has also been possible for the wiring harness and electrical connections to be reduced to a minimum. Based on a new load cycle strategy, the size of the internal parts could be reduced as well. With all these advantages and benefits, the 6-speed automatic transmissions are on their way to becoming state of the art for middle-sized up to luxury class vehicles. ZF is replacing their 5-speed transmissions with a complete, new product range which comprises 3 different transmission types. In 2005, the share of 6-speed automatic transmissions by ZF will be more than 90 %.