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).
Shock absorber noises, detailing discrepancies between drawings and shop practice and proposing solutions.
| Identifier | ExFiles\Box 55\4\ Scan315 | |
| Date | 23th February 1929 | |
| X235 OY4- February 23rd, 1929. TO: Mr. Poole Mr. Burton Mr. Ainsworth Mr. Allen cc - Mr. Robotham/London File cc - Mr. Beaver Mr. Soutter Mr. Southern Mr. Humpston Mr. Caswell Mr. Ingham Mr. Wilkinson FROM: Mr. Olley SHOCK ABSORBERS - SECTION 7150/60 Please read the attached memo from Robotham January 19th re shock absorber noises. In view of our complaints from certain districts it is obvious as Rm.{William Robotham - Chief Engineer} says that "the noise becomes an obsession." (20) The analysis of causes should be very useful to us. (1) I find discrepancies between our drawings and shop practice which should be rectified at once. (a) Since about chassis 2001 we have held the side play of the link to about .006 whereas the drawings still give .014 to .018. Measurement of our links shows that we hold the distance between the inside of the link members to .380 while the lever and eye remain .374. We should change the levers F-74896 and F-76382 and Eye F-74884 to .374 - 1 and the thickness of the pin F-73963 to .377-1. (b) Also the bore of lever F-76382 should be changed from .625+1 to .625+1/2 to be standard with the other two. (2) We do not seem to be troubled by the swaging out of the ends of the pins described by Rm.{William Robotham - Chief Engineer} But our pins have a burr on the edge as received in fitting shop. A .005-.010 chamfer at 45° on these corners would be desirable. (3) Rm.{William Robotham - Chief Engineer} in a sketch shows a .062" oil hole through the middle of the link to lead oil from the center bore to the fitting dia. This is only a proposed experiment. We should not adopt oil holes till we hear from England. We have seen no signs of seizure and it looks as though the oil holes might do more harm than good, unless they were carefully held vertical when rivetting the pins. (4) In the same sketch Rm.{William Robotham - Chief Engineer} shows slotted and drilled valves of the type we use as a proposed cure for the more severe rocking shaft knocks to which he refers, and which we have had in the past when the bushings were not a good enough fit. | ||