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).
Design and testing of a P.2 synchro mesh gearbox, specifically concerning the power of the cones and clutch inertia.
| Identifier | ExFiles\Box 179\1\ img050 | |
| Date | 26th October 1931 | |
| HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} ORIGINAL DA{Bernard Day - Chassis Design}1/M26.10.31. x7310 C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY P. 2. SYNCHRO MESH GEARBOX. We are laying out a synchro mesh engagement for the top and 3rd. speeds on P. 2. on the lines of the 25H.P., and shall send it to Derby so that Derby carry out the remainder of the box by scaling up the 25HP. There is however an important point which should be settled at once. This is the power of the cones controlling the clutch in P. 2. The moment of inertia of the clutch disc is approximately 3.2 times that of the 25HP. assuming the same thickness of the two discs, but we are only able to obtain an increase of cone dia. on the synchro mesh device of 33%. There is therefore some doubt as to the power of the cones on this box. We suggest that an experiment which could be immediately tried is to increase the moment of inertia of the clutch on the 25HP. box to correspond with that of the proposed P. 2. An exactly corresponding figure on the above assumption would be an increase of 2.4 times. Should the existing cones appear to have insufficient power we are able to alter the angle, and it will be necessary to determine the smallest angle we can do with. We should like a result as quickly as possible. In addition to the above R.{Sir Henry Royce} has asked that the torque given by the cones in relation to the load applied by the hand should be definitely measured. This may take a little longer, and though we wish for this information we suggest the first as being quicker and immediately useful. Could you at the same time as you measure the torque make an estimate of the force that is used by the hand in gear changing. We mean of course a comfortable maximum force. DA.{Bernard Day - Chassis Design} | ||