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).
High-speed steering wobbles and tests with hydraulic damping.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan131 | |
| Date | 25th August 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. To R; from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to DA.{Bernard Day - Chassis Design} RG.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG25.8.25. ORIGINAL HIGH SPEED STEERING WOBBLES. +457 48430 We have now conducted preliminary tests with hydraulic damping. (a) Between the cross steering tube and axle as previously carried out with Hartford shock absorbers. (b) Between the axle and frame in place of the normal front shock absorbers. The main difficulty which we have so far encountered is to induce the hydraulic element to function satisfactorily. We have in every case used Houdaille shock absorbers. These are not very well made, there being a considerable diversityt in the performance of different units. In addition, although the makers claim uniform results under all temperatures, we find that the viscosity of the fluid medium (castor oil) varies when it has become warmed up on the road thereby altering the effective setting of the control valve. This is very marked after a continuous wobble. We carried out all tests with balloon tyres and normal tyres. The low pressure tyres used in these tests were 7.3" section, run at an inflation pressure of 20 lbs/sq.in., and balanced. The high pressure tyres (33 X 5 cord) were inflated to 35 lbs/sq.in. It was necessary to have the wheels 1 lb. out of balance in the latter case, in order to obtain wobbles of sufficient violence. contd :- | ||