Tolerance Rings And Bearings Improve Powertrain Performance

Dual mass fly wheel

Decoupled pulley

When we think critical, under-the-hood car parts, we envision tough metal parts operating under the harshest conditions involving high heat, cold, and grime of all kinds. Plastics may not even be a consideration here, unless you’re the folks at Saint-Gobain Performance Plastics.

The company’s latest offerings, RENCOL tolerance rings and NORGLIDE self-lubricating plain bearings, promise to significantly improve the performance of automotive powertrain components. Both the tolerance rings and self-lubricating plain bearings are viable for use in dual mass flywheels (see fig. 1) while the NORGLIDE bearings find employment in decoupled pulleys (see fig. 2) in the belt driven accessory system.

According to Saint-Gobain, the automotive market is demanding components that can operate at higher torque and temperature levels, which obviously challenge the durability and longevity of systems using pulley decoupling forces generated by an elastomeric connection between the two components. The company’s response to these demands are reflected in its latest designs. These rely on energized springs that initiate mechanical decoupling and a NORGLIDE plain bearing handles the higher temperatures and aging factors of the elastomeric connection.

NORGLIDE bearings feature a fluoropolymer-based functional layer that is reinforced by a metal backing. Compared to roller or ball bearings, which can suffer from a lack of grease take-up due to the high-frequent small movements of system, NORGLIDE bearings are maintenance free, less expensive, require less space, compensate for minor misalignments, and reduce noise, vibration, and harshness.

RENCOL tolerance rings, described as precision fasteners, are manufactured from stainless or hardened carbon steel. Their unique geometry allows them to behave like radial springs.  Press fit between mating components, the tolerance rings compensate for manufacturing variations as well as the various thermal expansion properties of materials. For further information on RENCOL and NORGLIDE components, visit www.bearings.saint-gobain.com/rencol-tolerance-rings.aspx and www.bearings.saint-gobain.com/landingimg.aspx?id=211150. SAINT-GOBAIN CERAMICS & PLASTICS, INC., Worcester, MA. (508) 795-5000.