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 requesting a suitable propeller shaft for a Bentley car and detailing issues with the existing component.
| Identifier | ExFiles\Box 148\4\ scan0019 | |
| Date | 26th April 1933 | |
| X484 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}11/KT. April 26th 1933. Benjamin Whittaker Esq, Victoria House, Southampton Row, London. W.C.1. Dear Sir, We are sending you an arrangement drawing of the propeller shaft fitted to our Bentley car showing also details of the end couplings. The shaft has to run up to 4500 r.p.m. and transmit a top gear torque of 180 lbs.ft. 1st gear torque is about three times this amount. We hope you will be able to supply us with a suitable shaft for this car having, of course, the needle type joints. If you would first let us know the expected weight of the complete assembly we would compare it with our own. We are very anxious to reduce the weight of this component. A trouble we have experienced, as we told you this morning, is that the sliding joint does not slide when transmitting a large torque. This is noticeable when getting away from a standstill, the winding up of the axle, employing Hotchkiss drive, pushing the gearbox and engine backwards and forwards. Also the additional load causes failure of the thrust race for the axle bevel pinion. Tests have shown that a 300 lb. end thrust is required to slide the joint when transmitting 150 lbs.ft. torque, the unit pressure on the splines being 950 lbs/sq.in. assuming the load equally distributed among the twelve splines. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||