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).
Introduction of a ventilated Borg & Beck clutch for the Wraith model.
| Identifier | ExFiles\Box 129\3\ scan0336 | |
| Date | 10th July 1936 | |
| To E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} X1110 Hs{Lord Ernest Hives - Chair}/Smth.17/KW.10.7.36. Wraith Clutch. Whilst designing the Wraith we think we ought to take this opportunity of introducing the ventilated type of Borg & Beck clutch. This type has almost completely replaced the non-ventilated type in America, and is rapidly doing so in England. Its merits are claimed to be better durability, possibility of using weaker thrust springs, and less sponge in the operating mechanism owing to the stiffer cover. The ventilated clutch is interchangeable with the present type. We have had two or three of these clutches running about and find the take up and general performance to be no different from the non-ventilated kind. We have not, however, been able to take advantage of the ventilation as there has been no provision for air circulation in and out of the clutch pit. We attach a print of the clutch and also one showing the type of clutch case recommended by Borg & Beck. The special arrangement of the air outlet holes has been necessary to obviate whistles. We do not think that the holes in the clutch case will cause trouble from road dirt if they are covered with gauze. Many cars have completely open clutch housings. Whether or not the fan action of the clutch will aggravate leakage from the rear main bearing will have to be seen. One important aspect of the matter is that all other Borg & Beck customers are rapidly going to the ventilated clutch and we may have increasing difficulty in getting the present type. At the present moment only one other firm, who take 400 clutches a week, are using the 11A3 type, and they are shortly changing over. Hs{Lord Ernest Hives - Chair}/Smth. | ||