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).
The dynamic balancing of 25 HP crankshafts using a Trebel balancing machine.
| Identifier | ExFiles\Box 103\3\ scan0170 | |
| Date | 30th January 1933 | |
| DY.{F R Danby} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} C. to Sft.{Mr Swift} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}16/KT.30.1.33. DYNAMIC BALACING OF 25 HP. CRANKSHAFTS. Y1482 This work was done on the recently purchased Trebel balancing machine. This machine has two pointers indicating the movement of the ends of the shaft, and a considerable amount of time was spent attempting to damp out the vibration to which the right hand pointer was subject. This trouble was finally almost eliminated - at any rate very much lessened - by substituting a rubber driving band for the previous canvas one. It was found necessary to have a very loose canvas band as well as the rubber one to take the accelerating torque. When the shaft reached its running speed (480 R.P.M.) the drive is transferred to the rubber band. Five standard 25 HP. crankshafts and flywheels complete (with clutch assembled except for the driven plate) were then taken, and the out of balance at each end measured by means of this machine. The position of the out of balance was noted, but it was not thought necessary to record this as the matter under investigation was the average accuracy of the present system of static balancing. The results are recorded on the attached sheet and indicate that average maximum out of balance does not exceed 2.5 oz. ins. Hs{Lord Ernest Hives - Chair}/(C.S.Steadman). | ||