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).
The design scheme for a helical second speed for Bensport, detailing modifications and bearing considerations.
| Identifier | ExFiles\Box 179b\1\ img265 | |
| Date | 14th January 1933 | |
| PT. FROM HDY.{William Hardy} C. to BG. WOM. HS.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} P-H.{Arthur M. Hanbury - Head Complaints} HDY{William Hardy}/1/14.1.33. X4543 BENSPORT - HELICAL SECOND SPEED. We send herewith X. sch. 3636. and 3637. which shows the permanent scheme of helical 2nd. speed for Bensport. It will be seen that the box is .650" longer than with straight tooth gears, but the servo shaft is moved back only .125". There appears to us to be room for the extra length of box and slight rearward movement of the servo without alteration to the frame or brake gear. We have utilised the extra room to get a substantial bearing on the layshaft, more robust teeth on the coupling, and greater length of engagement of the coupling teeth than for the Peregrine. To obtain the maximum cross section of the casing between the races it is necessary to spot face for the rivet washers on one side. The use of a roller bearing with lips on both races would simplify machining, but we have had no experience with bearings of this type. Would Derby kindly enquire whether they have the standard load capacity, and also whether the end thrust that is required to move the outer race when limits for a sliding fit are used (max: interference .0002) is well within the capacity of the bearing. HDY.{William Hardy} | ||