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).
Series of tests conducted on a PH.III steering gear to investigate a rocking shaft fracture.
| Identifier | ExFiles\Box 153\1\ scan0301 | |
| Date | 16th May 1939 | |
| 1360 . 850 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/PJH. c. EK. c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. WHC. c. Mx.{John H Maddocks - Chief Proving Officer} Rm{William Robotham - Chief Engineer}/PJH.3/MR.16.5.39. PH.III STEERING. In connection with the recent fracture of a steering gear rocking shaft on the Paris demonstration chassis 3.DL.58, we have been carrying out tests to determine under what conditions this could occur. Test 1. The first test consisted of rigging up a production Ph.III steering gear so that the pendulum lever could lift a progressively increased weight off the floor. The result of this test was that the 3/16" dia. rollers inside the roller follower crushed at a load equivalent to 2050 lbs. in the side steering tube. This represents 2.2 times normal maximum load. The shaft was not twisted. The second test consisted of oscillating the pendulum lever very violently in an effort to fracture the shaft by fatigue. Test 2. Gear exactly as present standard. 3/16" dia. rollers crushed within 15 secs. and before rig could be run up to full speed. Shaft unaffected. Test 3. Gear fitted with ball-bearing type roller FD.{Frank Dodd - Bodies}330 proposed for remainder of 'D' series and replacements. Balls crushed and lip of inner race broken off after 1 1/2 mins. running at full speed. Shaft unaffected. The third series of tests consisted of running the Ph.III dyno chassis 30.EX. into obstacles in various ways to produce an impact load on the steering mechanism. A very good method of measuring the load in the side steering tube was suggested by H1/GSP. and was used. This consisted of an alum. pad in contact with a steel ball. The diameter of the impression produced is a measure of the load. | ||