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).
Discussion and series of questions regarding steering dampers, friction surfaces, and the effects of lubrication and load on vehicle handling.
| Identifier | ExFiles\Box 28\4\ Scan288 | |
| Date | 7th August 1925 guessed | |
| contd :- -2- it put on temporarily, probably in the form of the Houdaille ordinary axle damper, but we do not think it will require any valves, and for experimental purposes would be fitted with a by-pass which could be regulated, providing the fit of the vanes in the drum were too close. It seems that the fluid should be made to work uni- formly over the whole range of the steering and such a device may be beneficial in reducing the road shocks arriving at the hands of the driver, and also prevent low speed wobbles. Such a damper should be capable of moving slowly without resistance, and also prevent the sudden taking charge when the steering is carried over to a big lock in cornering. We understand that you are fitting on one car plain friction surfaces which can be adjusted, and which will probably take the form of a Hartford shock absorber, and on another car you are fitting the hydraulic arrangement in the form of a Houdaille shock damper, with some modifications to it internally by cancelling all the valves and possibly cancelling any clear-ance in the centre of the stroke. In thinking over the matter we should be glad if you can get several people with several cars on this job, as it is of the utmost importance, and also look up your records to ascertain some of the following :- (a) What percentage of the steering force is used (1)in the tyre,(2)in lifting the car, and (3) in the damping friction as at present arranged, when standard and if possible when driving slowly? (b) One feels that the friction of the journal bearings of the pivot may increase tremendously for want of lubrication, but that owing to the great freedom when lubricated, this friction can be relied upon for damping. (c) Is there any difference in the effect of damping by friction generated by the weight of the car, and damping friction steadily applied by a separate spring? We could not see any xxx advantage of one over the other until more recently when we think that a constantly loaded friction surface by spring may vary much less than friction generated by the weight of the car, because in the latter case the vibration may let in oil. (d) Is there any difference between lubricated and un-lubricated damping friction? I think there may be different results from damping friction dependent upon dry surface spring loaded, and damping friction dependent upon lubricated surface loaded by the car only, xx the latter being possibly very variable? (e) Is there any difference between damping friction required for the low speed, and the damping friction contd:- | ||