ZF launches the world’s first 9-speed automatic transmission (9HP) for passenger cars with front-transverse engines. Its particular features: great efficiency thanks to a high gear spread with close gear stepping, compact design, a smart modular kit principle, and high-speed and comfortable gearshifts. These benefits convinced Land Rover, the British premium car manufacturer: ZF’s new 9-speed automatic transmission stages its first volume production performance in a Land Rover later in 2013.
“We are delighted about the market launch of our latest transmission innovation, the new 9-speed automatic transmission for front-transverse applications. This is a new success chapter for our long-standing cooperation with Land Rover”, says Dr. Gerhard Wagner, Member of the Board of Management responsible for the Powertrain Technology division at ZF Friedrichshafen AG.
The 9HP, which is produced at the new ZF location in Gray Court, South Carolina, USA, will be launched in volume production in a Land Rover towards the end of 2013. Next item on the agenda is the trade show premiere at the Geneva Motor Show from March 7-17, 2013, where Land Rover will already present the new transmission to the public.
Customized advantages
Compared to the previously standard 6-speed automatic transmissions for front-transverse installations, ZF’s 9HP considerably cuts fuel consumption and consequently also CO2 emissions. The technical basis for the great efficiency of the 9HP is the very high transmission spread – and nevertheless, it is possible to have particularly small gear steps thanks to the nine gear stages. This not only enhances ride comfort but also makes sure that the engine always runs in the most economical speed range.
Revolutionary transmission concept
ZF realized the high number of speeds of the 9HP with the help of four individual gearsets and six shifting elements. It was a special challenge to place all these components in the transmission: After all, due to the design principle of passenger cars with front-transverse engines, the available transmission installation space is very limited. For this reason, the gearsets have not been allocated one behind the other on the 9HP’s longitudinal axis but were intelligently nested in. This concept was supplemented by using hydraulically operated constant-mesh elements: They can be integrated without major impact on the transmission length and feature a high level of efficiency.
A torque converter is used as the standard starting element in the 9HP. Here, a multi-level torsion damping system minimizes hydraulic losses by quickly closing the torque converter already at low speeds. With its direct engine connection, it reduces fuel consumption and enhances comfort as well as driving dynamics. For an even more superior driving experience, ZF has designed all control components for shorter shift times and response times that are below the threshold of human perception.
Direct multiple gearshifts are also possible with the 9HP and give the automatic transmission its sporty character. Thus, the transmission control unit can be influenced by the OEM and the end customer: Shifting points and shifting dynamics are highly variable – from an emphasis on comfort and optimized fuel consumption through to extremely sporty.
Flexible construction kit
ZF has prepared the new 9-speed automatic transmission as a modular kit so that it can be used in as many vehicle applications as possible. With two model ranges, it covers a torque range between 200 and 480 Nm. In addition, it is start-stop capable as a standard without an additional oil pump – and it can be hybridized: On the basis of a parallel hybrid architecture, the torque converter is then replaced by an electric motor. Not least, ZF’s 9HP has an open software and interface structure and a powerful electronic control unit. This means that it will be possible to integrate it flexibly into the most different vehicle concepts.
