ROLLING UNIT

摘要

A rolling unit which has rolling elements comprising a sintered compact of alumina having an alumina content of 99.5 mass % or more and exhibiting a flexural strength of 320 MPa or more as measured by a three-point bending test according to JIS-R1601, wherein the sintered compact of alumina is composed of crystal grains having an average grain diameter of 2 mum or less and a ratio of the standard deviation thereof to the average grain diameter of 0.4 or less, and has an inner ring and an outer ring both comprising the above sintered compact of alumina, a sintered compact of zirconia or a synthetic resin. The rolling unit allows the provision of a rolling bearing which has an excellent corrosion resistance and also is free from the occurrence of dry friction between a rolling element and a raceway groove even when a liquid present within the bearing is of a trace amount, and thus can maintain stable performance for a long period of time.