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).
Balancing propeller shafts to eliminate vibration, detailing tests and the effectiveness of a Trebel machine.
| Identifier | ExFiles\Box 148\4\ scan0013 | |
| Date | 3rd November 1932 | |
| 8484. Wor.{Arthur Wormald - General Works Manager} From Hs{Lord Ernest Hives - Chair}/Cry. c. to By.{R.W. Bailey - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Sft.{Mr Swift} X485 BALANCING OF PROPELLER SHAFTS We had found that with the new type of transmission on Peregrine in which the front end of the propeller shaft is attached to a crossmember and not to the gearbox that the propeller shaft is very susceptible to small amounts of out of balance which cause a violent vibration in the car. We therefore balanced a shaft on knife edges, the universals and tube being done separately. It was still rough in the car and the roughness was eventually eliminated by the addition to the front universal of 35grms at 1.625" radius. We therefore had the shaft in its original statically balanced state, dynamically balanced completed on a Trebel machine. This required a frame to support the shaft so that the universals could not bend. This frame was first corrected for dynamic unbalance. The propeller shaft was then tested and was found to be 35.8 gramms out at the front and slightly less at the rear, confirming our results. The test apart from mounting the shaft in the frame took about 5 minutes. Washers were temporarily added to correct this unbalance the shaft then running smoothly in the machine. The Trebel machine was very easy to operate and is direct reading on two scales of the amount and position of the balance, the balancing operation being effected by turning two handles consecutively until the vibration recorded on the needle disappears. This takes 2 or 3 minutes for each end of the propeller shaft. The machine is sensitive to 1/15 oz. ins. out of balance. It is a great improvement in ease of operation on the Olsen & Benrath machines we saw in use at Morris Motors. | ||