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).
Page 2 of a letter to the Institution of Automobile Engineers discussing brake squeak and μ-speed curves.
| Identifier | ExFiles\Box 121\1\ scan0069 | |
| Date | 24th October 1938 | |
| Institution of Automobile Engineers. -2- to zero speed. The general shape of the μ-speed curve can then be seen. We enclose graph 'A' showing the shape of the record. We should be very interested to know how you eliminate the temperature effect. In the paragraph of your report named "Origin of Squeak" (pages 16 & 17) you say that it is the friction-speed characteristic that is responsible for squeak, and with this we entirely agree, but your curves, Fig.13, hardly bear out your statement, whereas our curves, A.{Mr Adams} & B., do. We enclose two pictures of the somewhat crude apparatus we use to take these μ-speed curves. The speed of rubbing is measured by the time clock, not the speedometer. We very much regret that we have not more time to give to experiments on this subject, because squeak is a perpetual worry to us, and only by going for fundamental causes can it be permanently cured. We should be very much obliged if you would send us a picture of your μ-speed measurement apparatus, and also for a description of how you take the record: and if Mr. H.R. Mills, or yourself, are ever in the neighbourhood of Derby, we should be very pleased to discuss this aspect of the brake squeak problem with you. Yours faithfully, For ROLLS-ROYCE LTD. | ||