From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Endurance test report for a 'New Departure' Ball Race, part number 88507.
| Identifier | ExFiles\Box 114\2\ scan0170 | |
| Date | 26th June 1935 | |
| FOR FILES. X1020 Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} 26.6.35. "New Departure" Ball Race - 88507. Endurance Test. To date this race has been tested for 6 hrs. with the outer race free to rotate, and 20 hrs with the outer race held captive, the inner race revolving at 5000 r.p.m. After 30 mins. with the outer race captive, a small quantity of what appeared to be very thin oil sweated through the swaged joint. This sweating again appeared after 7 hrs. running, captive, and continued for the remainder of the test. There were no signs of any thick oil leaking either through the swaged or the felt joints. The running time was composed of periods varying from 1 to 2 hrs., the temperature of the bearing, measured at the end of these periods varying between 80° and 90°C. The same bearing is at present undergoing a 300 hr. endurance test at 1450 with the outer race captive. Hs{Lord Ernest Hives - Chair}/W.Bell. N.B. LJ.25 special R.{Sir Henry Royce} & M.{Mr Moon / Mr Moore} ball bearing has also commenced its endurance test. | ||