Today, ZF is the market leader in axle drives for conventional (front engine and rear-wheel drive) internal combustion engine drivetrain layouts. Thanks to significantly improved traction, stability and control, which result in enhanced safety and driving dynamics, the trend towards all-wheel-drive applications has contributed to the rise in demand for ZF’s proven axle drives over the past 20 years.
All-wheel drive boosts demand and safety
The success story for ZF passenger car axle drives began in 1997 when ZF produced the front and rear axle drives for the Mercedes-Benz M-Class at its Tuscaloosa (USA) site, with the bevel gear sets initially supplied from Passau. ZF took advantage of the boom in all-wheel drive vehicles and the resulting demand and opened new production plants for bevel gear sets and the assembly of axle drives in Thyrnau and Gotha (Germany), Gainesville, and Marysville (USA), as well as Shenyang and Hangzhou (China). Now, the ZF customer list for axle drives is longer and more international.
Ongoing development breeds success for broadest product range
Since the first product generation, ZF axle drives have been characterized by lightweight construction thanks to their aluminum housings. Thanks to its ground bevel gear sets, together with application-specific gear design, ZF has improved refinement and lowered noise levels. In subsequent product generations, the weight was further reduced through design optimizations and the efficiency was improved by using low-friction bearings and low-viscosity oils. “The increasing demand over the decades has enabled us to create a range of variants,” explains Kay Schmidt, Head of the Axle Drives Product Line. “We focused on modularization at an early stage, developing a system of standard components. As a result, we now have the world’s broadest range of axle drives to extract the best performance in any application.”
With the introduction of the controlled differential lock in ZF rear-axle transmissions in 2002, ZF was able to offer new mechatronic and electronic features as well as software control. The electronically-controlled differential lock allows variable torque distribution between the two wheels of the rear axle, which not only improves traction even further, but also enhances driving dynamics and driving safety. Now in its fourth generation, ZF has continuously developed this feature to benefit its customers.
For the increasing number of all-wheel drive vehicles with front-transversal drive configuration, ZF has developed a rear-axle drive with an integrated all-wheel drive clutch based on its expertise from the differential lock. This is a complete system consisting of mechanical, mechatronics and software elements to deliver all-wheel drive functionality. This product is complemented by a power-take-off unit (PTO) installed on the front axle, which directs torque to the rear axle according to the requirements determined by the all-wheel clutch.
Based on its purely mechanical axle drive solutions, ZF also offers software-controlled, intelligent solutions with extended functionality for mild and plug-in hybrid vehicles (MHEV, PHEV) applications. Just like the standard axle drives, they are characterized by a low power-to-weight ratio, low noise levels, and good efficiency – all essential for such powertrains.
The production anniversary proves that know-how and innovative spirit are well received worldwide. 40 million times – and the counter continues to run.
SOURCE: ZF
