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).
Report on the flexibility of a fabric coupling and its potential to cause clatter during declutching.
| Identifier | ExFiles\Box 74\3\ scan0068 | |
| Date | 31th January 1929 | |
| OY5. CU191 January 31st, 1929. TO: Mr. Burton Mr. Caswell Mr. Soutter cc - Mr. Southern Mr. Ainsworth Mr. Knapton Mr. Fuller Mr. Poole Mr. Ross Mr. Robotham (England) FROM: Mr. Olley RE FABRIC COUPLING Section 6020 In connection with our idea that the fabric coupling might by its flexibility contribute to clatter on declutching, we have the following report from Mr. Robotham. "---It will be observed that the relative stiffness of the coupling is tremendously high compared to the rest of the transmission." (See SK-283) In view of the much greater stiffness of the coupling disc than the transmission-line from rear of gearbox to rear tires, and the enormous damping-effect in the coupling disc(as shown by the "hysteresis-loops") it does not seem reasonable to claim that the fabric coupling is responsible for clatter. Yet we have the observed fact that after 8000 or 10,000 miles, as the coupling disc becomes more flexible (which is confirmed by the chart) there is a distinct increase in clatter. It would be interesting and useful, as soon as we can, to find the torsional flexibility of the transmission line from rear of gearbox to rear wheel rims, excluding the tires, and see how this compares with the flexibility of the coupling disc. We know that when the rear of the car is jacked up the transmission system appears to oscillate between the rear wheels as flywheels and the engine flywheel. Tire flexibility does not enter into this effect. If this latter stiffness should compare with the stiffness of the coupling disc we might expect the bulged fabric to give slightly more tendency to clatter than a new plain disc because of its less damping effect. OY. POST STAMP: POST 13 FEB 1929 RECD | ||