IDEX 2015: Equipped for Difficult Missions – ZF's New Automatic Transmission EcoLife Offroad

• ZF presents advanced automatic 7-speed transmission system for medium and heavy military vehicles
• Higher gear ratio spread bolsters climbing capability 
• ZF-EcoLife Offroad is more powerful, more economical, and quieter than rival products 

Whether on difficult terrain, extreme cold, or critical situations, a military vehicle must always be reliable. That requires enormously robust, tailor-made transmission technologies. The new 7-speed automatic transmission ZF-EcoLife Offroad for medium-heavy and heavy special vehicles not only meets these requirements. It also makes vehicle operation very cost-effective, handles up to 2 600 Nm of torque, improves acceleration, and shifts gear depending on topography. Thus drivers can concentrate entirely on challenging maneuvering.

Powerful, compact, and economical: The advanced ZF-EcoLife Offroad with 7 gears sets new standards for automatic transmissions in medium and heavy military vehicles. (Photo: ZF)

ZF has developed a new transmission in the shape of the EcoLife Offroad, which is ideal for current and future requirements placed on off-road, multi-axle, or all-wheel-drive military trucks as well as heavy armored wheeled vehicles. Tailored exactly to the particular vehicle, it relieves the driver entirely from having to operate the clutch and gear lever – thus preventing any stress-related incorrect operation. The new ZF transmission also offers clear advantages over comparable competitor products in many other important criteria.

The key characteristic is the high spread of ratios of 9.1, which, on the one hand, facilitates high speeds, while significantly improving the vehicle's climbing ability on the other. The EcoLife Offroad is also perfectly suited for more powerful engine generations, as it effortlessly copes with high input torque of up to 2 600 Nm – and transfers this with no loss of tractive force while shifting gear. In conjunction with the new torque converter, which features an integrated torsional damper, this ensures jolt-free setting off, good acceleration figures, and pronounced smoothness even from low engine speeds – on extreme off-road inclines as well as on the road.

The power-to-weight ratio of a transmission is relevant when it comes to optimizing the payload of military vehicles: It must therefore not only be able to transmit very high torque in absolute terms, but also be as light as possible itself. The dry weight of the EcoLife Offroad basic transmission – despite all the usage-relevant reinforcements – is just 450 kilograms. It is also very compact at just approximately 900 millimeters long, which saves valuable installation space. Thanks to the helical-cut planetary gearsets, the automatic transmission operates remarkably quietly – another advantage particularly for military applications.

The ZF-Retarder, which is integrated directly into the transmission, comes into its own particularly on long downhill gradients. This hydrodynamic, wear-free continuous service brake effectively slows down the vehicle thanks to a maximum 1 900 Nm of braking torque and relieves the strain on the service brakes, thus reducing wear by up to 90 percent. The entire retarder effect is also retained during gearshifts. EcoLife Offroad is also prepared for potential auxiliary power units: In future two power take-offs will be available with a maximum 1 000 Nm of torque.

Durable and Future-Proof 

With EcoLife Offroad, the successful concept of the ZF-EcoLife for city buses was further developed and adapted to the tough use in military vehicles. EcoLife Offroad does not only use the advantages of the economical and efficient basic transmission, but is also equipped with reinforced components.
Compared with comparable, current competitor products it can actually intelligently and reliably handle demanding military applications and offers a longer service life. Even the service portfolio of the transmissions from the ZF-Ecomat family used worldwide to date in this area could be improved further.

EcoLife Offroad also comes with a dual cooling system. This comprises an integrated oil cooler and a separate retarder oil cooler. All of which makes the ZF automatic transmission future-proof from another important aspect: It has been designed from the ground up for the kinds of higher temperatures which new engines need in order to fulfil increasingly stringent exhaust emission standards such as Euro 6, EEV, or EPA 10. Not least, the EcoLife thus provides an important contribution to making heavy trucks as well as armored wheeled vehicles more economical and hence environmentally friendlier.

Tailor-Made Electronics

An electronic control unit forms the brains of the ZF-EcoLife Offroad. To minimize necessary wiring, this is fully integrated into the transmission. Programmed specifically to each particular vehicle, it communicates via a standardized CAN bus interface (CAN SAE J1939) with other vehicle components.

Tried-and-Tested Base Saves Costs

In order to equip the EcoLife Offroad for extreme loads, ZF has pushed the technology to a new level. Nonetheless it remains economical for the customer, as this specific transmission is also based, like many others at ZF, on a sought-after volume-production product: Its technical base, the six-speed automatic transmission ZF-EcoLife, is fitted to city buses around the globe. With EcoLife Offroad, ZF consistently expands its existing transmission portfolio for medium and heavy military vehicles, making it fit for the future.