What Is A Composite Bearing?

Polygon’s line of PolyLube™ bearings uses a fiberglass filament wound structure in a proprietary epoxy resin matrix for a a very high strength bearing that is naturally concentric with no seam or overlap. This high strength laminate construction allows for thin walled bearings (1/16" to 1/8"), reducing the size and weight of the assembly. The results: a composite bearing which exhibits a very low coefficient of friction coupled with high load-bearing capacity.

PolyLube™ Liner Design

PolyLube bearings utilize a proprietary design that ensures the anti-friction backing is locked in with more than simple adhesion. This gives excellent resistance to impact fatigue and cavitation problems.

MRP fiber lining Fiber series lining

The PolyLube™ Fiber and MRP series bearings have their liners applied in a dry manufacturing mode. They are inherently very resistant to impact because the liner backing uses high strength fiberglass filaments interwoven into the liner backing.

Polygon's liner construction show dramatic improvement during:

  1. Break-in–improved coefficient of friction and wear change.
  2. Contamination–dirty or unsealed environments
  3. Long term–improved bearing life.

Differences in liner construction can also impact performance in the following areas:

Go Greaseless!

PolyLube™ bearings exhibit excellent load capacities, low frictional values, resistance to corrosion, and also allow for true self-lubrication. All secondary lubrication systems and their design guidelines can be eliminated from industrial applications.

Journal bearing static load comparison Journal bearing dynamic load comparison Greased VS greaseless journal bearing comparison

Desired Characteristics Of Journal/Plane Bearing Materials

In general, journal/plane bearing materials should have the following characteristics in order for the bearing assembly to be properly designed:

  1. Truly Self-Lubricating. Many materials claim to offer some self-lubrication, but lose this quickly during operation. Sintered metal structures are especially prone. When the lubrication fails, metal-on-metal contact results, leading quickly to premature bearing failure.
  2. Embeddability.The bearing liner should absorb or “embed” within itself wear debris or airborne dirt particles.
  3. PV Rating. This should be easy to understand, and fit most applications with a good match between the bearing pressure and surface velocity capabilities.
  4. Quick Transfer of PTFE Film to Shaft. The key to self-lubricating bearings is the rapid transfer of PTFE from the bearing ID to the shaft surface during initial break-in. The film functions as a dry lubricant, reducing friction and wear rate.
  5. Fiber Orientation to Minimize Friction. A low coefficient of friction is possible when the contact surface is on the ends of the PTFE fibers.
  6. High Percent of PTFE Near the Surface. More PTFE near the surface of the bearing provides more dry lubricant for wear and friction reduction compared to deeply embedded fibers.

What our “Composites Revolution” Means To You

Polygon is the only organization with composite self-lubricating bearings as a primary product focus, unlike any other company in the journal bearing market. Other bearing organizations see composite bearings as a necessary offering only to satisfy the design needs of the OEM market.

Polygon is singularly focused on fiber-wound composites as our core competency. That focus means we can better engineer the performance of these bearings and define what factors improve product performance. Our strong manufacturing infrastructure is there to support your business needs. Our abilities as an organization to specify sizing, assembly, and design parameters are unmatched in the self-lubricating composite bearing industry. Why? Because it is what we do. The value to you? Polygon has the best designed, highest performing bearing material available, at the best cost in the industry.

The True Value Of Self-Lubrication

Greased journal bearing Greaseless journal bearingToday’s design engineering community must continually search out materials that improve performance capabilities in conjunction with total cost of operation.

Experienced OEM design engineers know that poor lubrication is one of the most common failures for bearing designs. In theory, a bearing design that is properly sealed and lubricated should provide trouble-free service. The reality is that greased joints are often not maintained properly. As a result, the boundary/mixed lubrication condition diminishes and the bearing life is limited.

In addition, the total cost of ownership for standard lubricated bearing is greater than that of a self-lubricating composite bearing. Maintaining a greased bearing joint is 1.5 to 4 times the cost of a self-lubricating bearing joint for most OEM’s clients. They bear the cost of purchasing, assembling, and maintaining grease systems. Equipment rental yards are becoming increasingly sensitive to the liability associated with greased bearings.

External lubrication introduces an uncontrollable variable for OEM engineers. Once the finished product is shipped to the customer, the customer must properly maintain the bearing assembly. This introduces a potential for failure, and whatever liability or warranty claims may come from that. If proper maintenance is a concern, the best solution is a self-lubricating composite bearing, since it fully lubricates the contact surfaces, does not attract dust or dirt, results in no environmental problems as grease or oil can, and requires absolutely no field or long term maintenance.

Journal bearing total cost of ownership

When To Use PolyLube™ Bearings

Hex ID and special ID shapes are possible Polygon can customize CNC designs