Comparative evaluation of metal and polymer ball bearings

A second set of tests was conducted to compare the performance of these polymers with stainless steel in similar bearings. 8 mm polymer ball bearings and 8 mm metal bearings under dry lubrication conditions were used in these tests. Performance is compared using vibration, acoustic emission as well as changes in the rotational speed. A lower level of vibration is observed with the usage of PEEK in the bearing elements when compared to that of PTFE and metal. However the transfer film formation in PEEK bearings resulted in unstable operating speed of the bearing. Stable operating speeds after an initial running-in period is observed due to transfer film formed in carbon-filled PTFE bearings. However a higher level of vibration is observed in this material when compared to that of the PEEK bearings.