BUEHL, Germany, June 4 /Xinhua-PRNewswire/ -- Almost 20 years after the successful development of the Dual Mass Flywheel (DMF), automobile supplier LuK has set yet another milestone in vibration damping. Through the compact integration of a centrifugal pendulum-type absorber, the damping capacity of the Dual Mass Flywheel can be increased by an additional speed-adaptive component. In this way, LuK ensures optimal driving comfort, including for the upcoming high-torque engine generations.
The centrifugal pendulum-type absorber is mounted on the flange of the Dual Mass Flywheel. The necessary effective stiffness of the pendulum is generated by the centrifugal force during operation. The centrifugal pendulum-type absorber has no set natural frequency and changes the frequency depending on the speed. It is therefore known as a "speed-adaptive absorber". Efficient absorption of the selected vibration level, e.g. the ignition frequency of the engine, can be achieved through appropriate tuning. A pendulum mass of just one kilogram is all it takes to reduce the transmission by up to 60%. The basic insulation of the vibrations is still carried out by the Dual Mass Flywheel with spring mass damper system, residual vibrations are eliminated by the centrifugal pendulum-type absorber through the absorption of the ignition frequency.
The new absorber also offers advantages with regard to installation space. The pendulum replaces the inner damper found in conventional Dual Mass Flywheels, taking up no extra space. Centrifugal pendulum-type absorber DMFs can therefore be used wherever a standard Dual Mass Flywheel is already installed.
LuK developed the Dual Mass Flywheel in 1985 to help combat gearbox rattling caused by increased speed - a torsion damper made up to two masses connected together with a damping spring system. Since then, the DMF has been developed continuously and adapted to suit the increased engine performance and comfort requirements of the customers.
The idea of the centrifugal pendulum-type absorber has been in existence for decades and is already used in aircraft engines. The high required pendulum mass of approx. 5kg and the complexity of the engine application prevented the knowledge gained in aircraft construction to be applied to the requirements in the automotive field. Only in conjunction with a modern Dual Mass Flywheel did LuK succeed in finding a viable application solution enabling the centrifugal pendulum-type absorber to be incorporated in the drive train.
Dr. Juergen Kroll, manager of the Dual Mass Flywheel product line at LuK, underlines the robust nature of the innovation: "The centrifugal pendulum-type absorber DMF was subjected to extensive series of tests focussing on function, material wear and safety-relevant aspects. The result was clear: this Dual Mass Flywheel guarantees optimal driving comfort designed to last for the entire service life of the vehicle with no symptoms of fatigue."
The internal results recorded at LuK were confirmed in a series of tests carried out for customer projects. The first centrifugal pendulum-type absorber DMF is due to enter series production this summer for an international premium automobile manufacturer.
About the Schaeffler Group
The Schaeffler Group, with its brands INA, LuK and FAG, and approximately 66,000 employees at more than 180 locations in 50 countries generates group sales of more than 8.9 billion euros (FY 2007) and ranks amongst the leading rolling bearing manufacturers and suppliers to the automotive industry worldwide. Affiliated companies include Schaeffler KG with its head office at Herzogenaurach and the brandnames INA and FAG, as well as the LuK Group, whose head office is located in Buehl/Baden.
