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).
Detailed analysis of historical hub, axle, and bearing design issues and their solutions.
| Identifier | ExFiles\Box 84\4\ scan0107 | |
| Date | 17th September 1936 guessed | |
| - 2 - Regarding trouble with the hubs coming loose on the taper, this is unknown at K, as is the case with any difficulty in re-fitting a taper accurately after removal. If you will examine the general layout of the old type Bentley chassis, you will find that the designers were very keen on the 1 in 10 taper and a key; and from my own practical experience with this Company, spread over 17 years now, both service, new work and racing, I have yet to see any flange, hub or gear, which has worked loose after once being properly secured - in fact the trouble very often is that we have to use excessively strong extracting rigs if we wish to remove the offending flange or hub. Not knowing the purpose of your enquiry, I am offering additional information on the subject of rear axles in accordance with my experience with the old type models. You will notice that the earlier type, or in fact all the old type Bentley chassis with the exception of the 8-litre and the 4-litre, used the Timken race piece No. 435/4320, which is a 1 5/8" bore by 3.4843" outside diameter. If you examine the axle tube ends of the earlier type cars, with the exception of the 8 & 4-litres, you will notice that the adjustment for 'end float' in the road shafts is by means of a cap screwed on to the end of the Timken bearing housing. Bearing in mind this method of adjustment, you will readily see that the Timken outer race had to be a sliding fit in the axle end housing, consequently we experienced a certain number of Timken failures due to lack of support for the outer ring in cases where the bearing housing was slightly oversize, the outer ring on this particular bearing being in itself of small cross sectional area and not up to its job. These fractures that occurred were of a curious nature. The race would crack and expand after the manner of a tube expander, the outer ring enlarging the diameter of the axle end as much as .02". To overcome this, the 8-litre was designed for Timken No. 535/532a, 1 3/4" bore by 4.375" outside diameter, which allowed of a better cross sectional area for load distribution from the ring to the axle tube end. There have been no failures with the large type Timken. -contd- | ||