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).
Testing the effect of a clutch disc on transmission rattle for Chassis No. B.22.AW.
| Identifier | ExFiles\Box 130\3\ scan0147 | |
| Date | 30th December 1940 | |
| 1110 To Rm.{William Robotham - Chief Engineer} From Rp/DB.{Donald Bastow - Suspensions} Copy to Mr/Wyn. Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Rm{William Robotham - Chief Engineer}/GB.9/BT.{Capt. J. S. Burt - Engineer}30.12.40. EFFECT OF CLUTCH DISC ON TRANSMISSION RATTLE ON Lp.{Mr Lappin}'s B.V (Chassis No. B.22.AW) This car suffered from transmission rattle as follows:- 1. Rattle was bad at 26 m.p.h. in overdrive with its own clutch and its own fully floating rear axle. 2. Rattle was present in direct (3rd speed) up to 35 m.p.h. 3. There was no rattle with a semi floating axle. 4. There was no rattle with a new disc with fully floating axle belonging to Lp.{Mr Lappin}'s car. It is obvious from the above that there was some difference in the torsional rate, friction or spring set up between the disc which was on Lp.{Mr Lappin}'s car and the new disc which was fitted to it. The object of the present tests was to find the difference in torsional characteristics between the disc which came from Lp.{Mr Lappin}'s car and new discs, and thus to find out how to cure transmission rattle in the disc. The torsional characteristics of the disc from Lp.{Mr Lappin}'s car and of four new ones were measured. There were such large variations between one new disc and another that it was not possible to ascertain the cause of transmission rattle in the disc from Lp.{Mr Lappin}'s car. To do this it will be necessary to measure the new disc which has been fitted to Lp.{Mr Lappin}'s car. The curves from the four new discs and the one from Lp.{Mr Lappin}'s car are attached. It will be noted that the depth of the friction loop on the new discs varies from 15 to 50 lb/ft. The tests were carried out on the rig shown in the sketch on page . To use the rig a spring test machine had to be improvised. This was done by putting a 2500 lb. platform scale on stands under the large drilling machine. Rm{William Robotham - Chief Engineer}/GB. | ||