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).
Letter from Ferodo Limited concerning clutch and brake linings for the Goshawk clutch.
| Identifier | ExFiles\Box 26\4\ Scan169 | |
| Date | 11th January 1923 | |
| R.R. 199 (250T) (S.D.676 19-7-17) MP 180865 COPY. FERODO LIMITED., SOVEREIGN MILLE, CHAPEL-EN-LE-FRITH. Ref. FJF/DHL. 11th January 1923. Messrs. Rolls Royce Ltd., DERBY. For the attention of Mr Bailey. Dear Sirs., Spring Interleaving - Clutch & Brake Linings. We have pleasure in confirming the interview kindly given to the writer on Tuesday last, and appreciate the opportunity of personally discussing the many interesting features arising in above connection. We hope you will be able to send us a set of springs for fitment with our interleaving for trial, as only road and bench tests can establish the advantage we claim for our method of improving spring action and maintaining constant condition between the plates. In regard to the condition arising in the Goshawk clutch, we are very concerned to know that such comparatively heavy clamping pressure is required for adequate working. We should have given no more than 700 lbs for 105 foot lbs. torque, making the co-efficient of friction 0.25 with an allowance of approximately 160 lbs. In this regard we would refer you to particulars given on page 29 of our Plate Clutch booklet - copy herewith. The value 0.3 we found under test conditions was forthcoming with full slip of the lining against a hard steel plate at any temperature up to 500° Fahr. We will set up 10.375 x 8.25 linings in the machine and will advise you of what follows from pressures, if you could arrange to see similar tests here. If we can demonstrate as we have confidence in doing, the pressure required in your clutch will pick up and maintain higher torques than your engine expresses, it may indicate some condition in the clutch itself that militates against the efficiency of the friction surfaces. Yours faithfully, FERODO LIMITED. | ||