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).
Report discussing the viability of welded joints and various floating axle designs, with references to issues at Rover and Leyland.
| Identifier | ExFiles\Box 114\1\ scan0053 | |
| Date | 24th September 1936 guessed | |
| (sheet 4) There is no method known at present of testing a weld on production to determine its soundness, and any failure arising therefrom would be likely to arouse considerable criticism, having regard to the selling price of the chassis. We think our conditions of operation are more akin to that of the higher grade commercial chassis which have to carry very heavy loads at high speeds over big mileages, and Leylands have told us that under no circumstances do they agree to use welded joints under direct loads. With regard to the question of the half and three quarter types of floating axle, this is a matter on which we have already done some design investigation, and our proposal was to test one of these out as an alternative. The chief objects we had in mind were reduction of slack in the drive, and saving in weight and cost. We are aware however that considerable trouble has been experienced with wheel hubs mounted on tapers, and that these once disturbed were often a source of trouble afterwards. Structurally also there is nothing to beat the full floating shaft in which the axle casings carry the wheel bearings and the centre shaft is only employed for driving. Where the centre shaft is called upon to not only drive but carry the weight of the car and the lateral bending moment arising from the side loads on the road wheels, there have been numerous cases of failure. The Rover Co. for example told us that they do get a certain number of failures which results in a rear wheel breaking off. The Rover failures always takes place in the threaded portion of the axle shaft which carries a nut for securing a ball bearing. In a recommended scheme put up by Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} there is a similar thread, but we believe the consensus of opinion of the majority of people who use this type of axle is that a thread in this position should be avoided. Rovers are experimenting with an electrical upset axle shaft which enables them to avoid this thread. The Leyland Co's representatives told us that they had built a certain number of half floating axles, but their experience had decided them never to use this type again. In the Leyland case breakage was experienced in the taper of the shaft and not at the point of maximum bending moment in spite | ||