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).
Modifying 20 HP exhaust fittings (schemes 563 & 564) to eliminate vibration.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan4 | |
| Date | 20th March 1924 | |
| B.R. 495a (20H) (D.A. 652 20-3-24) J.B.D. EXPERIMENTAL REPORT. -1- Expl. No. REF JM.{Mr Morley}/TWS/1/Gen.9; 34 20 HP. MODIFIED EXHAUST FITTINGS. SCHEMES 563 & 564. Complaints were received some time ago of a low speed exhaust pipe vibration of varying speed and intensity which was being experienced on production. As a temporary measure of improvement, a bracket was standardised securing the exhaust pipe to frame, and it is now proposed to abolish this and substitute one of the above schemes. Further investigations have shewn that this vibration originates in the silencer, which, being suspended by two rather flexible brackets, communicates the movement to the exhaust pipe where it is considerably amplified by reason of the length of pipe. Schemes 563 and 564 have been evolved from these investigations and are both successful in eliminating vibrations. It will be seen that the silencer is held rigidly to the front cross member, the rear being suspended by a flexible bracket, as at present, to permit of expansion. The Exhaust Pipe is connected to the silencer by means of a sliding joint which ensures that it shall never be stressed by expansion. The movement from cold to hot in this joint is as much as .375" and this accounts for the varying periods and intensities of the vibrations on different chassis, as at present produced. It is also appreciably noticeable when fitting either of these scheme that there is a distinct lessening of the over-run vibrations with closed throttles, together with a reduction of the contd :- | ||