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).
Technical memorandum discussing the issue of squeaking brakes and potential solutions.
| Identifier | ExFiles\Box 26\4\ Scan314 | |
| Date | 19th November 1926 | |
| To Hy.{Tom Haldenby - Plant Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to WOR.{Arthur Wormald - General Works Manager} X719 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}5/LG19.11.26. SPRINGFIELD. X8470 QUESTION 24. With reference to Hy{Tom Haldenby - Plant Engineer}36/W16.11.26. We have no definite cure for squeaking brakes. The best palliative which we have so far tried is to attach dampers in the form of a ring round the brake drums. Attached are blue prints (G.75353 and G.75352) of an arrangement we are at present trying out on the lightened type Phantom front axle. We do not consider that the rivets on the brake liner should stand flush with the surface of the material. When the liners get to this condition, we consider that they are about worn out. The friction material is heavily countersunk, and the heads of the rivets should be 1/8 to 3/16 below the surface, when the liner is new. We have tried numerous types of Ferodo both soft and hard, oily and dry. We have found nothing which will prevent squeaks and yet give good wearing life. We consider that on the lightened type front axle, brake squeaks will be a serious problem and suggest that the brake drums should be increased in section as far as is permissible by the present design, as it is our experience that very flexible brake drums promote squeaks. We have carried out some tests on brake bedding which have shewn us that brake squeaks almost always occur when the initial point of contact of the shoe with the drum is near the heel. When the shoe is eased off at the heel and brought on at the toe, brake squeaks disappear. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||