Self-lubricating Composite Bearings

• flexible design

• cost-effective

Bearing manufacturer Polygon Company recently came out with a line of self-lubricating composite journal bearings constructed using Teflon PTFE fiber from DuPont. Ben Shobert, vice president of marketing at Polygon, points out that with metal and alloy bearings, performance characteristics are finite. On the other hand, composite components — fiber reinforcement, resin and additives — can be changed to meet the needs of the application. 

Beyond the familiar characteristics of the resin used in non-stick cookware, PTFE fibers are processed to a higher degree of molecular orientation, making the stress-strain properties and resistance to cold flow markedly different than those of the resin. Teflon fiber offers various features that are suitable for bearings. It has a lower coefficient of friction than other known fibers and its dynamic cf decreases with an increase in load or temperature. It is an excellent insulator and is highly chemically resistant, with a wide thermal operating range. It also sports UV and weather resistance, absence of stick-slip and nonflammability. 

The PolyLube MRP bearing can withstand static loads of approximately 60,000 psi, and dynamic loads at 30,000 psi. The oriented Teflon multi-filaments in the composite are the primary anti-friction components in the bearing’s ID. The bearing is highly stable and operates in temperatures ±325°F. Polygon specifically heat-stabilizes the bearings at these temperatures to diminish dimensional change during operation. The coefficient of expansion is comparable to that of steel, and less than other metals.

The total cost of ownership of a greased bearing, with the maintenance and downtime, can be approximately 50% greater than that of a self-lubricating bearing. Shobert says, “OEMs using a PolyLube MRP bearing may be able to reduce costs by changing pin material, eliminating fabrication steps required for grease fittings, the zerk itself and the cost of the grease system.” The bearings are suitable for applications with impact or impulse loading stress, such as construction and material handling equipment.

For more information:
Polygon Co, Walkerton, IN.  www.rsleads.com/204df-277

DuPont Advanced Fiber Systems, Richmond, VA. www.rsleads.com/204df-278