The Evolution of Polymer Bearing Processing for Scroll Compressor Performance and Life Enhancement

Polymer bearings with a PTFE-based running surface were first introduced as a breakthrough in scroll compressor performance over 30 years ago. These bearings consisted of the polymer surface, porous bronze interlayer and steel supporting layer. That bearing construction has become widespread in compressor applications, while the bearing composition and performance have advanced, with improved environmental impact. Since that introduction, polymer application to the bronze bearing interlayer has relied on the deposition of a composite slurry to produce the low-friction, wear resistant surface. While that deposition method has served the compressor application well, bearing life was basically limited by the polymer integrity and layer thickness that were determined by the inherent nature of the slurry-based process.  A new material technology has been applied to scroll compressor bearing manufacture to provide notably improved performance both in durability and seizure resistance in comparison to the historical slurry-based deposition method. This comparison has been documented through the utilization of  wide-ranging laboratory-scale tribological testing to measure both the durability and starved-lubrication properties in conditions relevant to scroll compressor conditions as well as general tribological testing.  A comparison of the bearing materials manufactured by the two process technologies will be provided as well as tribological results documenting the performance enhancement. Test data presented will include results from the bearing development and manufacture and qualification tests by a prominent compressor manufacturer, documenting the improvement in both durability and seizure resistance