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).
Impressions on the Goshawk model regarding chassis weight, dynamo drive noise, and clutch pedal stiffness.
Identifier | ExFiles\Box 42\2\ Scan073 | |
Date | 6th September 1922 | |
H.R. 233A (500 T) (S.D. 408-26-4-17.) Bm. 2/156/13. To HS.{Lord Ernest Hives - Chair} & EP.{G. Eric Platford - Chief Quality Engineer} from R.{Sir Henry Royce} c. to CJ. BJ. PN.{Mr Northey} C. c. to Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} Cx.{Major Len W. Cox - Advertising Manager} ORIGINAL SEP 6 1922 RECEIVED Go' RR R1/M.9.22. W.J.H. rating Re-examined RE. GOSHAWK In confirmation of the decisions arrived at during your visit to WW. on the 31st ult., the following are my most vivid impressions:- (1) That someone has suggested a 9 cwt. body for the Goshawk. This confirms my impression that this chassis should only be guaranteed if the weight carried by it does not exceed a certain figure to be decided. My impression is that its maximum weight with all on including all passengers should be 35 cwt. If it is allowed to grow more than this it will compete with the 40/50, and will not give satisfaction for so many reasons, principally that we shall not have enough engine power. (2) Much time was spent on ascertaining the reason for a very slight noise in the dynamo drive and it was suggested by me and generally agreed upon that it was possible that unless the gear between the crankshaft and camshaft were without slack and that there was no end play on these shafts, that the camshaft might over-run it's drive and knock in all the gearing. That is what occurs in all cars including the 40/50s. We had hoped however when we had as in Goshawk 11. loaded the camshaft with the various units, that it would not over-run it's drive. Apparently we have very nearly done this, and possibly the use of thick lubricating oil would just about give the balance. I have suggested however that we fit a wider pump so that we shall increase the load on the gears on the slower speed. Some extra provision might have to be made to prevent this pump exceeding the pressure decided, when running at the high speeds, when the oil is cold. Some confirmation of this conclusion is required by Mr. Hives. It has since occurred to us that possibly at slow speed running even the crankshaft turns irregularly owing to there being 3 impulses and 3 compressions per rev. even though small such impulses will vary the speed and hence all the unit will knock even if first drive were absolutely without slack. In which case friction in spring drive will only increase the tendency for the secondary drive to knock, whereas if the knock comes from the uneven resistance of the camshaft it would only be necessary to make the first pair of gears tight or sufficiently loaded to allow all the other gears to be quite slack. A few experiments with this in view will shew which is the source of the slight knock in the dynamo drive. (3) CLUTCH PEDAL. I cannot help thinking that the clutch springs which are being fitted are unnecessarily and undesirably stiff. There seems such an enormous difference between the pressure required on the pedal of this production chassis compared with No.4.& 6. Goshawk 11. and it is certain that unless these springs can be materially reduced we cannot send the cars out unless we alter the leverage of the clutch pedal mechanism as has been instructed. My impression is that we ought to do both - (1) | ||