I am seeking advice for our application, which is a completely non-metallic wagon carrying an electromagnetic transmitter/receiver system. The current wheel bearing assembly has failed. It consists of zirconia-toughened alumina (AZT) bushings (~ 4" long, inserted into the wheel rims) with a carbon-fiber-reinforced-polymer shaft (a thin-walled, 1" O.D. tube) as a fixed axle. Failure occurred when the bushing abraded the shaft enough to seize, causing the shaft to rotate and to break free of the restraints on the wheel housing. A field repair (cleaning and reassembly with liberal amounts of white lithium grease) lasted two days, until the shaft itself broke in two. The load on the wheel ~60 lb, nominal service speed ~1 rev/sec, short-term max. speed ~4 rev/sec. Any ideas (especially using other materials with the same bushing-bearing design approach) would be greatly appreciated.
The load on each wheel is 60 lb (120 lb total load on the shaft).
Make the bushings from wood. Or, use traditional laminated wood oxcart wheels. Use lots of grease, and don’t expect miracles for a lifetime.
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