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).
Technical memorandum detailing test results for the low inertia slipper wheel, focusing on driving and friction loads.
| Identifier | ExFiles\Box 137\4\ scan0065 | |
| Date | 6th December 1929 | |
| To By.{R.W. Bailey - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c. to E.{Mr Elliott - Chief Engineer} RIC. Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}1/AJ.6.12.29. LOW INERTIA SLIPPER WHEEL E.79915 S.S. X 634 We have carried out numerous tests both on the test bed and on the road to obtain the driving and slipping loads most suitable for all purposes. The driving load and friction load must be taken separately. The driving load should be minimum 20 lbs maximum 25 lbs to bring the springs just off choc-a-block (i.e. .005" clearance) at 17 1/4" leverage. Springs E.77646 should be used and not springs E.76636 which are too weak and cause a tendency to clank. The friction load should be maximum 25 lbs. minimum 20 lbs. at 17 1/4" leverage using springs E.776637. We have reported upon the necessity of ironing out the cotton duck washers, otherwise the above load will not be obtained and will not be constant. We find that the thickness of the washers should be approx. .050" after flattening out to give the required load. They are .062" in the first instance. We find that if the friction load is greater than 25 lbs bus knocks are prevalent. If below 15lbs. crankshaft periods become noticeable. There is a tendency for engine gear rattles under load, therefore it will be necessary that no magneto pinion should be fitted with more than normal clearance. We have not been able to entirely overcome this trouble without running into crankshaft periods. The best setting to overcome engine gear rattles is a driving spring giving a load of 30 lbs at 17 1/4" leverage and a friction load of 10 lbs at 17 1/4" leverage but these loads do not cope with crankshaft periods therefore we cannot recommend them for production purposes. Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} | ||