Flexible construction kit system

HP transmission sizes

The 9-speed automatic transmission, which has been in volume production development for some time, is designed for torques up to 480 Nm (9HP48), a smaller version for engines up to 280 Nm is planned (9HP28). In future, the total engine range of vehicles of front-transverse configuration shall thus be covered.

To ensure that the 9HP can be used for as many vehicle applications as possible, it has been prepared as a construction kit: An additional transfer case can be connected for the all-wheel drive operation. The engine performance is then distributed to front and rear axle at the transmission output. For an efficient implementation of such an all-wheel drive, ZF developed a system with decoupling function (AWD Disconnect). It actuates the rear-axle drive only when it is needed and thus, saves five percent fuel compared to the permanent all-wheel drive.

The 9-speed automatic transmission is also start-stop capable without a hydraulic impulse oil storage (HIS). Since, in the case of restarting, it is only one friction shift element that needs to be closed, response times are indeed highly spontaneous. In addition, the 9HP can be hybridized: On the basis of a parallel hybrid architecture, the torque converter is then replaced by an electric motor. Finally, thanks to its open software and interface structure as well as the powerful electronic control unit, it will be possible to integrate the 9-speed automatic transmission flexibly in different vehicle concepts in terms of function and electronics. This diversity of the 9HP construction kit makes the transmission especially efficient.