Both can be used in dual mass flywheels while the use of NORGLIDE® bearings in decoupled pulleys in the belt driven accessory system of modern vehicles has contributed to a change of design.
Originally, pulley decoupling forces were generated by an elastomeric connection between the two components but recent industry demands for higher torque and temperature operation have stretched the durability of such systems. In the latest designs, energised springs initiate mechanical decoupling and a NORGLIDE® plain bearing is included in the system to cope with higher temperatures and aging issues of the elastomeric connection.
NORGLIDE® bearings have fluoropolymer-based functional layer reinforced by a metal backing. The pulley application uses NORGLIDE®’s full potential, including the ability to specify components with specifically tailored geometries and sliding surface compositions.
A dual mass flywheel (DMF) smoothes engine pulses by transmitting torque to the transmission through two flywheels connected by springs. The oscillating motion between the flywheels is much better suited to the properties of NORGLIDE® bearings, which are virtually maintenance free, than roller or ball bearings which can suffer from a lack of grease take-up due to the high-frequent small movements of system. In addition, NORGLIDE® bearings are less expensive, require less space, compensate for minor misalignments and reduce NVH (noise, vibration and harshness).
RENCOL® tolerance rings are also used in DMFs. These precision fasteners, manufactured from stainless or hardened carbon steel, have a special geometry that allows them to behave like radial springs. They are press fitted between mating components – in the case of the DMF, a flange and fixation ring. As their name suggests, RENCOL® tolerance rings compensate for manufacturing variations or the different thermal expansion properties of materials and offers advantages in NVH. However, in the case of the DMF, the component also provides overload – or shock – protection by allowing joined parts to move relative to each other above a pre-determined torque.
These, and other, powertrain solutions not only take full advantage of the unique characteristics of RENCOL® and NORGLIDE® products, but also draw on the combined expertise of the organisations behind them, which have now been brought together in Saint-Gobain Performance Plastics.
In addition, the company has a large and active research and development department that allows it to take full advantage of advances in materials and processes, and an extensive testing facility which ensures that all of its products and solutions fully and reliably meet the user’s requirements.