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).
Visit to Borg & Beck discussing friction issues and design changes for 10-inch clutch discs.
| Identifier | ExFiles\Box 130\3\ scan0164 | |
| Date | 31th January 1941 | |
| To Mr. Crees Bs{A J. Barnes - Assistant Manager}/HS.{Lord Ernest Hives - Chair} Copy to Mr. Bs{A J. Barnes - Assistant Manager}/SJH. Bs{A J. Barnes - Assistant Manager}/Sym. Ev{Ivan Evernden - coachwork}/Tln. 1110 Bs{A J. Barnes - Assistant Manager}/HS.{Lord Ernest Hives - Chair}3/T.31.1.41. VISIT TO BORG & BECK 29.1.41. The items on this visit were:- 1. Friction in 10" clutch discs. 2. Modifications to Borg & Beck's design of 16" twin plate clutch (Tank). 3. Operating mechanism of 16" twin plate clutch. 4. 14" clutch for tank steering. To simplify filing, items 2 to 4 are dealt with in a separate memo. 1. FRICTION IN 10" CLUTCH DISCS. We know that clutch disc friction, if of the right magnitude, can cure transmission rattle. We therefore require discs whose friction can be maintained within reasonable limits. The discs supplied by Messrs. Borg & Beck in the past have shown considerable variations in the depth of the friction loop. Some reasons for this and the discussion around them are given below. A.{Mr Adams} Insufficient length in the riveted collars resulting in severe local nip of the hub flange adjacent to the collar. This is bad because the spring in the discs does not have a chance to make up for the variations in the length of the spacer collars. The sketch used to show Messrs. Borg & Beck the difference between nipping the hub disc adjacent to the spacer collars and through the shim is included in this memo. Borg & Beckhoffer to grind all faces and make individual friction tests on each disc supplied was rejected. Instead small design changes were requested, which would make the amount of friction less dependant on fine dimensional limits. Borg & Beck are to supply three sample discs with spacer collars .005" longer than standard, each with a different quantity of friction to be obtained as follows:- One disc to have no standard shim. One disc to have two standard shims on one side of the hub flange. One disc to have one standard shim on either side of the hub flange. | ||