Active Roll Stabilizer

Today’s market demands that modern motor vehicles should offer extensive safety packages, the greatest possible comfort and optimized dynamic behavior. This cannot be achieved without the use of regulated actuators, which is why the use of actuators has increased dramatically. This is why active roll stabilizer systems have been available for some time, which are mainly fitted with hydraulically-operated actuators.

These roll stabilizers have been introduced as semi-active or fully active systems. The fact that the fully active system has a positive influence on driving dynamism - and therefore on safety and comfort - is well-established.

The active stabilizer uses a torsion spring to link the left and right sides of the vehicle. When used in conjunction with a corresponding regulating mechanism, it can influence torque coupling in such a way that the rolling movements of the vehicle are dramatically reduced. The regulating action of the active stabilizer must offer very broad coverage between the required dynamism and the demand for torsional rigidity. This is because ensuring comfort with one-sided application of loading, in other words the comfortable “uncoupling” of the two sides of the stabilizer, requires a highly dynamic release of moment. On the other hand, disturbances even under high torque load, for example when taking bends at speed, must be excluded.

The OVALO drive system is based on a brushless OVALO hollow shaft engine and an OVALO precision gearbox. The challenge for developers is to use an electromechanical actuator to attain or even exceed the control achieved in the market to date using hydraulic systems.
The functional models already shown indicate that we shall succeed in mastering this challenge. The overload capability of the drive mechanisms and the high reduction of the gearboxes mean that very compact hollow shaft engines can be fitted. However, an innovative control concept and the associated power electronics are essential, whereby the responsibility for developing these modules lies with our project partners from the automobile industry. Through close cooperation we shall succeed in establishing electromechanical roll stabilizers in production in the near future.

The advantages of the OVALO gearbox

  • Overload capacity
  • Hollow shaft
  • High energy density
  • Backlash-free and non-self-impeding