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).
Design and specifications for a 3.25' diameter piston for the 'China' Chassis, focusing on the circlip design.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan117 | |
| Date | 4th May 1929 | |
| FROM R.{Sir Henry Royce} SECRET R1/M4.5.29. C. to PISTON FOR 'CHINA' CHASSIS. X.5040 We are sending you herewith LeC. 2698. shewing the 3.25" dia. piston for 'O' series of twenties. The piston pin is retained by circlips and I have schemed that these latter shall be just plain spring rings without fancy ends so that there will be more chance of getting them right. These clips must be circular when in position, which means that when free the radius of curvature will alter from a minimum on the horns to a maximum opposite the split. The required shape should be determined to suit the conditions of load specified on the drawing. We calculate that at 4000 RPM. of the engine the maximum stress due to the inertia of the circlip is 23,000 lbs. per sq. in. in the worst position, and as we expect the set up stresses to be about 60,000 lbs. per sq. in. the clip should be quite safe. Four grooves are provided so that the rings can be extracted in any position. For shop use I think a special pair of pliers could be made for removing the circlips. This is such an important matter that we must spare no effort to get it as good as we know how. R.{Sir Henry Royce} | ||