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).
Visit to Ford Motor Co. to inspect their method of balancing crankshafts.
| Identifier | ExFiles\Box 126\3\ scan0077 | |
| Date | 16th February 1937 | |
| 1065 Hs{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c to E.{Mr Elliott - Chief Engineer} c to By.{R.W. Bailey - Chief Engineer} c to RHC.{R. H. Coverley - Production Engineer} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}8/M.16.2.37. Visit to Ford Motor Co. The main object of the visit was to inspect their method of balancing the crankshaft. Following the casting of the crank which is a low carbon steel of their own analysis, the crank is machined on the crankpins and the journals and the oil holes drilled. The crankshaft is solid throughout and the oil feed holes are drilled at an angle between the journals and the pins passing through the webs, such that one pin is fed from one journal. If satisfactory big end lubrication is obtained, then this method must be considerably cheaper than ours which entails internal machining, fitting of oilers, extra holes drilled in the webs with screwed plugs. The solid crank is, of course, heavier and is slightly stiffer though not in proportion to the increased weight. It could certainly not be considered for the big ends of a 6 cylinder engine. Following the machining operations the crankshaft is put on the initial and dynamic balancing machine which is capable of registering out of balance up to 10 oz. ins. These machines are a product of Tinius Olsen, Testing Machine Co., Philadelphia, U.S.A. and cost approximately 3,500 dollars and run at 260 r.p.m. Each end of the crank is balanced independently, the end which is being balanced is free to move about a bearing which is situated under the other end of the crank roller supports and visa-versa. Out of balance causes vibration of the whole of the machine, controlled by vertical strip springs, this being recorded electrically by a pointer on a dial in sparking unevenly to one side. In good balance even sparking takes place, this being obtained by an automatically operated corrective weight in which the angle of the weight can be varied relative to the crank also its balancing moment. When the machine is stopped the position of a coloured pointer on the correcting weight indicates the where material is to be taken off the crank balance weights, | ||