Abstract
Constant velocity joints (CVJs) are key building blocks of automotive drivetrains: all the power which drives the wheel must pass through the CVJs. Therefore the efficiency of these drivetrain building blocks has a significant impact on overall vehicle losses. Engineering research is concentrating on a reduction of the component losses to allow an optimization of vehicle fuel economy and CO2 emission. A new outboard joint concept called ‘countertrackTM’ could be successfully developed: this CVJ concept is providing as a step-change a reduction of component losses of more than 50% against the well-known Rzeppa concept. In 2009, as first evolution, the so-called SX8 was launched on European market for premium vehicle applications requiring 50° maximum articulation angle. With this paper, the design principle and the methodologies for design optimization of the latest product evolution, the so-called SX6, shall be introduced. Results of virtual modelling and testing will be discussed; furthermore the impact of the component losses on vehicle fuel economy will be quantified. With this innovation, a new fuel saving technology becomes suitable for mass market of front wheel driven vehicles.
KEYWORDS – Constant velocity joint; countertrack; driveshaft; sideshaft; fuel efficiency