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 drawing of a 1st speed synchro unit assembly, showing components, assembly instructions, and modifications.
| Identifier | ExFiles\Box 126\2\ scan0088 | |
| Date | 26th August 1938 | |
| TOP HEADER: HUMBER-HILLMAN COVENTRY. SK. MODIFICATIONS SHEET: CLASS | MODIFICATIONS | SHEET | DATE | SGN | LOCKING PLUNGER ADDED | 09/141 | 38 | R.B | K.W | SERRATED SYNCHRO CONE DELETED | | 11.8 | | | AXIAL LOAD TO CHANGE ADDED | 09/250 | 38 | L.N | NOTE RE SELECTIVE ASSEMBLY OF PLUNGER ADDED. DRG. REDRAWN | 09/353 | 13.9.38 | R.A DRAWING ANNOTATIONS: GEAR DOTTED SHOWN IN NEUTRAL. GEAR IN FULL LINES SHOWN IN 1ST. THE AXIAL LOAD REQUIRED TO MOVE 1ST SPEED GEAR IS 50 LBS TO 56 LBS. NOTE:- PLUNGERS FITTED INITIALLY IN PRODUCTION HAD ROUND ENDS AS SHOWN DOTTED. SELECTIVE ASSEMBLY OF GEAR & HUB TO BE CARRIED OUT. PARTS TO BE A GOOD SLIDE FIT, WITHOUT PERCEPTIBLE SHAKE. SELECTIVE ASSEMBLY OF THESE SPLINES ON MATING COMPONENT TO ENSURE THAT THEY ARE A GOOD SLIDING FIT WITHOUT PERCEPTIBLE SHAKE. (.0004 MAX: CLEARANCE ON BOTTOM OF SPLINES.) SELECTIVE ASSEMBLY OF PLUNGER, TO ENSURE THAT, WHEN TAPER ON PLUNGER IS HARD ON SIDE OF GROOVE, THE CLEARANCE BETWEEN HUB & BEARING IS .010" MIN, & .020" MAX. BOTTOM TABLE: FINISH SYMBOL DRAWN: C.A. 26.8.38 TRACED CHECKED PASSED SPEC? NOTE- ALL UNLIMITED MACHINING DIMENSIONS TO BE WITHIN +.200m/m -.200m/m M: MACHINED FINISH H: HARDENED G: GROUND X: MACHINE ALL OVER m: ROUGH MACHINE HEAT TREATMENT MATERIAL | SPEC N WEIGHT | LBS | OZ | FORM ROUGH | SECTION FINISH | LENGTH PART INFORMATION: COMPNT: GEAR BOX & MAINSHAFT. PART: 1ST SPEED SYNCHRO UNIT ASSEMBLY NUMBER: [Illegible/Scratched Out] STAMP: HUMBER HILLMAN STAMP: SEP 1938 | ||