PTFE/carbon composite radial deep groove ball bearings: Part 2 – fabrication and analysis of bearings for characteristics

Abstract

Tribological characterization was carried out in part 1 of the paper on pure PTFE (PTFE) and 25% carbon-filled PTFE (CR25) polymers through the ball-on-disc test to determine the suitability of the material for ball-bearing applications. This part focuses on fabricating and analysing CR25 and PTFE radial deep groove ball bearings for characteristics. An OR35-INST, a 6-channel DAQ system integrated with ORBI gate and NV-gate software, was used to record the vibration characteristics. Initially, a free run test was conducted, in which the shaft was supported on the fabricated PTFE/Carbon and PTFE polymer bearings and was rotated for two million cycles. Throughout the test, its RPM and vibrational amplitudes were continuously recorded. After one million cycles, the supported shaft’s dynamic characteristics (orbit and shaft centerline plots) were obtained. The free-run test results reveal that the shaft mounted on the bearing sets has excellent dynamic stability. Finally, a rolling contact fatigue test (RCF) was performed in which the fabricated polymer bearings were subjected to a variable radial load from 36 N to 108 N for one million cycles. The results show that the proposed PTFE composites can be used to develop ball bearings in low-load and RPM applications.