Thermosetting polymers for high speed bearings: linking friction and heat
Polymeric materials are used more and more as cage material for light weight bearing applications, but thermoplastic materials suffer from PV limits. At high speeds, the polymer may melt easily under light loads. Thermoset resins don't have this limit, but may still disintegrate under higher temperatures. In this method, we can apply high speeds and variable loads, to explore the limits of thermosets.
The Falex Block-on-Ring tester has a simplified journal bearing geometry and consists of a stationary block loaded against a rotating or oscillating ring. A stable line contact is created, where speed, load, temperature, angle of oscillation, specimen material and finish can be varied. For this work, high speeds are of interest. Friction forces are low, but the accumulation of temperature is giving useful information about the amount of friction dissipated in the contact, and whether the materials can withstand these conditions. Comparative testing can show the advantages of thermosets over thermoplastics for high speed applications.
- Ranking of different polymeric materials under experimental conditions that simulate the actual application is possible.
- The evolution of friction can be linked to the temperature, applied load and sliding velocity.