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).
Investigation and resolution of engine pulsation and vibration issues.
| Identifier | ExFiles\Box 25\3\ Scan072 | |
| Date | 28th April 1922 | |
| Hs.{Lord Ernest Hives - Chair} from EP.{G. Eric Platford - Chief Quality Engineer} c. to PY. c. to Wor.{Arthur Wormald - General Works Manager} [STAMPED: Hs{Lord Ernest Hives - Chair} APR 29 1922 REC'D] Re. ENGINE PULSATION AND VIBRATION. With reference to the above which has had your attention experimentally for some considerable time, the general policy being that these vibrations can only be cured by reducing the vigour of the engine, or isolating the engine from the chassis, we have recently had the PN.{Mr Northey} Trials car, 81-TW at the Works with this complaint. PN{Mr Northey} suggested at the time that the cure for this trouble should be the taking up of the crankshaft bearings, and the retuning of the slipper drive. In testing this car we did not feel, judging by the running of the engine that there was anything seriously wrong with the bearings, as the usual symptoms, so far as the running of the engine is affected, did not exist. Also although there was a certain amount of end-play in the crankshaft, this did not appear to cause any harm in regard to the running of the engine, and the vibration complained of still existed even though the end play was taken up by pressing on the clutch pedal. We felt we made a considerable improvement in the period vibration of this car by refitting the various body fittings about the scuttle and dash board etc. but the crankshaft bearings have been taken up at Cricklewood, and PN.{Mr Northey} in his report to OJ. which I showed to you yesterday writes as follows:- "All the crankshaft bearings have been found very slack. In the case of the middle main bearing some of the white metal has run from some cause or other, and the main thrust bearing was re-lined in order to take out the excessive end thrust movement. There was an end thrust movement of 25,000 ths of an inch, where a tolerance of 4,000ths. of an inch is allowed only. I tested the car on its return from Cricklewood yesterday, and you will be interested to know that I found the excessive vibration in the engine when picking up, has been so far improved and reduced, that the car as it stands is at least as good in this respect as the best chassis we can expect in production from Derby. This incident really becomes of special importance in view of the fact that with this car some of the highest officials of the company had virtually owned themselves beaten in the absence of some revolutionary change to the car. It has been demonstrated that by the simple process of taking up the bearings which have been too slack, a problem with this car has been solved, which appeared to CONTD. | ||