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).
Comparing specifications for different dashboard pumps used in centralised chassis lubrication systems.
| Identifier | ExFiles\Box 27\1\ Scan077 | |
| Date | 15th February 1929 | |
| BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} c. to Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} X.3806 DA{Bernard Day - Chassis Design}2/M15.2.29. CENTRALISED CHASSIS LUBRICATION - DASHBOARD PUMP. With reference to Hsl/LG5.2.29., we have prepared a design for a pump of larger capacity with higher pressure - N.Sch.2830 - sent herewith, to avoid the possibility of delay, but we are not quite clear as to the necessity for it. Our information (which may be out-of-date) is that the pump used on the American chassis is the hand operated one, the particulars of which, from drgs. and Mr.Bijur's information are :- Bore and stroke .650 X 2.750" Capacity .912 = 14.94 c.c. Pressure per sq. in.60 lbs. This pump worked satisfactorily. As compared with it our pump has been relieved of 5 rather thirsty components viz: Front axle. Universal joint and torque sphere. Rear axle. Front and rear springs. So that Mr. Royce's wish to make the pump smaller seemed justified. The recent proposal to include the road springs in the centralised chassis lubrication forms a possible reason for an increase now. Actually the corresponding particulars of the RR. pump as designed (N.Schs. 2647 and 2736) are - Bore and stroke 1.250 dia. X .750 Capacity .92 cu.ins. = 15.07 c.c. Press;per sq. in. (N.Sch.2736) 82 lbs. ) Max: originally 60 lbs. ) (It will be seen that our capacity figures do not exactly agree with Hsl/LG5.2.29). So far as we are aware the Bijur foot operated pump has not been used on a RR. chassis. (Our information regarding it is as follows) - Bore and stroke 1.5 X .7" Capacity 1.236 cu.ins. = 20.22 c.c. The pressure we do not know but take your figure of 124 lbs. per sq.in. giving a load of 219 lbs. and a spring stress of 156,000 lbs/sq.in. Mr. Bailey objects strongly to our exceeding 30,000 lbs/sq.in. because the resulting [stamped and crossed out] cannot be guaranteed. | ||