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).
Tests of a 20 HP rear axle bevel pinion thrust.
| Identifier | ExFiles\Box 20\7\ Scan115 | |
| Date | 12th June 1925 | |
| R.R. 4934 (So H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. COPY. Expl. No. REF: TESTS ON 20 HP. REAR AXLE BEVEL PINION THRUST. Comparative tests have been carried out with standard double thrust races for bevel pinions, New Departure No. 207 bearings and New Departure No. 306 bearings. The 1st. test was carried out with standard thrust races which had 2 rows of 5/16 dia. balls - 13 in each row. This was run for 20 hrs. at a speed of 2,000 r.p.m. with a load of 1,000 lbs. This represents Direct Drive conditions. After test all balls were badly scored and two were chipped. For the 2nd. test new races of the same type were fitted and run for 10 hrs. at a speedof 1,220 r.p.m. with a load of 2,500 lbs. On examination the balls were again scored and one had chipped badly. Races were also in a bad condition. This test represents 2nd. speed conditions. We then rigged up a New Departure Bearing No. 207 for the next test. On this type of bearing we measured the end float before and after test to enable us to arrive at what wear has set up during test. The bearing is fitted with 2 rows of 5/16 dia. balls - 14 in each row and was run for 10 hrs. at a speed of 1,220 r.p.m. with 2,500 lbs. load. This represents 2nd. speed conditions. On examination the bearing had failed. 3 balls having chipped badly. The next test was carried out with a New Departure No. 306 bearing. This bearing was subjected to a series of tests (as shown below) and is fitted with 2 rows of 7/16 dia. balls - 9 balls in each row. No. 1 test. This was run off 2,000 r.p.m. with 1,000lbs. load for 20 hrs. which represents Direct Drive conditions. The float in the bearing had increased by .001. No. 2 test. This was run off 1,220 r.p.m. with 2,500 lbs. load for 10 hrs. which represents 2nd. speed conditions. The end float being .001 the same as the previous test. No. 3 test. This was run off 700 r.p.m. with 4200 lbs. load for 10 hrs. This represents 1st. speed conditions. On examination this bearing was found to be quite good but the end float was .0015. No. 4 test. was run off 525 r.p.m. with 5,800 lbs. load for 10 hrs. contd :- | ||