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 for a spring-loaded piston for rear dampers.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan347 | |
| Date | 18th July 1931 | |
| NORMAL LOAD 9.4" REBND CHAMFER CORNERS HARD BRONZE OR C.I. MAX BUMP NITRO HARDEN .325" 1490 LBS FOR 200 LBS AT 13" RAD. MAX REBND. 130 LBS AT NORMAL LOAD POSN 30 LBS H.P. L.P. .250 NUTS RIVETED ON FOR CENTRELESS GRINDING DAMPER BODY UNALTERED WE SUGGEST THIS ALL THE WAY ALONG THE BOLTS FOR ECONOMY OF MANUFACTURE B.M. ON LONG BOLTS. H.P. DAMPING 200 LBS. THE B.M. ON THE BOLTS AND TENDENCY FOR THE PISTONS TO ROCK IS LOW IN THE RANGE OF MOVEMENT WHICH WILL COMMONLY OCCUR. AT THE EXTREME REBOUND THE B.M. IS CONSIDERABLE AND FOR THIS REASON WE HAVE PROVIDED .312 BOLTS. B.M. AT MAX REBOUND = 130 x 2.05 = 266 LBS INS STRESS = 266 / (2 x π/32 x .312^3) = 44,000 LBS/SQ" SPRING LOADED PISTON FOR REAR DAMPERS SCALE 1/1 PLAN 2 N.G.N. K.T. NSch 3225 SCHEME FOR USING EXISTING LEVER FORGINGS (NOT MACHINED). AS WHEN MACHINED THE HOLE IN THE EYE PREVENTS THE NECESSARY REDUCTION IN SIZE BEING MADE. PIN PRESSED IN HYDRAULICALLY. EACH SUCCESSIVE HOLE IS SMALLER THAN THE LAST SO THAT PIN IS TIGHT IN ALL THREE. FULL LOAD AS FOR P2 2 BA SPLIT PINNED SPRING LOAD 110 LBS MEAN DIA COILS .600 DIA WIRE .128 No EFFEC COILS 5.0 DEFLN. .290 STRESS 80,000 THE OIL PRESENT IN THE LOW PRESSURE END OF CYLINDER TENDS TO SEPARATE THE PISTONS BY ACTING ON THE LONG BOLTS. THIS ACCOUNTS FOR 70 LBS OF THE 110 LBS WHEN THE L.P. DAMPING IS 150 LBS (AT 13" RAD) PISTON ALIGNMENT THE CYLINDER COUNTERBORE INSISTS ON THE ALIGNMENT OF THE PISTONS BY THE BOLTS BUT IN ANY CASE WE PREFER THIS SCHEME OWING TO THE CONSIDERABLE CROSS-WIND ON THE PISTONS (AS ON DELCO). | ||