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).
Torque limits, shaft speed, coupling improvements, and material fatigue.
| Identifier | ExFiles\Box 181\M7\ img003 | |
| Date | 1st April 1924 guessed | |
| alternate (2) With alternate currents the max Torque is limited I understand to about twice full load Torque & does not need stiffer drive to prevent excessive strain or skidding wheels The cross results also show that your cross shafts should run relatively faster or be of larger dia, kindly examine all new work & make some improvements, cheaper to run them faster say 1/2 or 1/3 [illegible] motor speed. The coupling can be improved by larger bolts 3/4 instead of 7/16, I do not think the cone angle will make much difference it soon becomes mostly friction, another way is to use more bolts in numbers, say one on each side = 6 or 9 bolts, also one might weaken the bands by 4 5 or even 6 splits & fit each with its own 5/8 instead of 7/16 bolt If the outer band bursts it should be Cast in steel or made of wrought steel The shafting would break from fatigue with alternate Torque much below max strain, so that a small sheer stud might be enough for the friction grip with cross feather Keys for emergency. | ||