Linear Bearing,Slide Bearing:Self-lubricating bearing liner material reduces friction

Linear Bearings are relied upon heavily to reduce the friction generated by machinery. Self-lubricated slide bearings minimize friction between two surfaces by transferring dry lubricant to an uncoated, rotating shaft support. Once a stable transfer layer is set up, the polymer-to-polymer interface provides a low-friction, low-wear bearing system.

One of the more popular self-lubricating materials used in this capacity is polytetrafluoroethylene (PTFE) which can be bonded to the surface of metals such as stainless steel or bronze or woven with a polyester/glass fiber. PTFE has also been compounded with thermoplastic and thermoset polymers and molded into bearings. PTFE bar stock is commonly machined into bearing components.

Betty Snyder, project leader for W.L. Gore & Associates' Bearing Liner Material in Newark, Del., says, "PTFE bearings can create problems related to creep; poor wear resistance and difficulty in bonding as a coating. Many fillers and configurations have been developed over the years to improve these shortcomings, but there is still room for improvement."

PTFE appears to readily flow away from the load zone during periods of stress, which can lead to performance deficiencies. This means that PTFE does not always provide the balance of low coefficient of friction, self-lubrication and low wear desired in bearing operations.