A Three Year Test

THE PROVERB “ the proof of the pudding is in the eating ” is just as true in engineering subjects as it is in any other field. With engineering, the eating is the operation of the equipment by the customer on site over a considerable period, which in most cases, would be measured in years of operating time. Unfortunately, the reporting of performance over such a long period is all too scanty to enable the equipment manufacturer to improve his future products. The problem we are to consider in this article is the grease lubrication of rolling bearings operating at speed factors in the region of 300,000 mm/min.