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 specifications for hypoid gears, including off-set sizes, component changes, and gear ratios.
| Identifier | WestWitteringFiles\Q\April1927-June1927\ 19 | |
| Date | 14th April 1927 | |
| TO BY, FROM DA.{Bernard Day - Chassis Design} ORIGINAL. DA{Bernard Day - Chassis Design}3/M14.4.27. C. to BJ. HS.{Lord Ernest Hives - Chair} EAC.10. - HYPOID GEARS. X2066 X8310 X7310 With reference to R4/M7427, we did not understand that R.{Sir Henry Royce} intended to scrap the 2" off-set hypoids. We believed that those with the 1" off-set were intended as a reserve in case trouble was experienced with the first ones. For one thing we cannot do with less than 2" to take full advantage of these gears in lowering the frame as proposed on EAC. 9. The 1" off-set only permits us to correct the faults that exist on EAC. 7. at the present minute, and we shall not be able to get the frame any lower. We are not quite certain what R.{Sir Henry Royce} intends, and shall discuss the matter further with him, but in the meanwhile we have prepared N. sch. 2399. herewith shewing a pair of hypoid gears that a 1" off-set. It will be seen that only two new pieces are required apart from the actual gears, namely, a new centre s casing, and a new bridge piece, so that the bulk of the details already prepared for the 2" off-set gears are still available. We believe that Gleason's have asked for rather wider teeth, and since we can do it without trouble here, we have shewn them 1.8" wide instead of 1 3/4". We have rather gone beyond the spiral angle limits which Gleason's indicated when the gears were first announced, and they may not approve of the spiral angles. We do not intend to tie them down. We have only shewn one ratio - 11/41 - and will send you others if necessary after we have discussed the matter with R.{Sir Henry Royce} DA.{Bernard Day - Chassis Design} | ||