I've worked on this problem for over 5 years without success. A machine I am familiar with has a chronic bearing failure problem. Specifically, the cage disintegrates after about 6 months. The bearing is used in a vibratory application. An eccentrically weight shaft impels a total mass of about 2000 kilos with a force of 12 g's max at a frequency that does not exceed 600 cps [usually closer to 300 cps]. The bearing cage invariably fails after about 1200 hours. The cage rivets break, apparently due to fatigue. We even tried a one piece cast bronze cage [very expensive], and it too broke. The bearing manufacturers' engineers are stumped, as am I. Any ideas? ps - no evidence of lubrication failure.