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).
Bench and road tests analyzing friction in the steering pivot head.
| Identifier | ExFiles\Box 67\2\ scan0274 | |
| Date | 26th January 1928 | |
| 78420 To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. 7 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}6/T26.1.28. ------------ X. 8420 X. 8425 X. 8430 FRICTION IN STEERING PIVOT HEAD. ----------------------------- We have carried out a number of bench and road tests on the axle with spring shunted friction in the pivots to N.sch.2296. As a general result of the road tests we find that we cannot obtain quite such good results with N.sch.2296 as with the friction in the cross steering tube. This is not, we believe, because there is any inherent difference between the two methods of applying the friction, but because N.sch.2296 does not allow us to provide so much friction under the car running conditions as the spring loaded ball ends. By carrying out a static test in which 1300 lbs. was suspended from the stub axle we have measured that the friction torque available from the standard pivots due to the wt. of the car is 400 ins.lbs. To this we are adding a torque of 375 lbs. friction due to the spring loaded cross steering tube. Therefore the total stationary friction torque on the pivots is 400 + 375 = 775 ins.lbs. Now on the type of road on which we get complaints of joggles, we estimate that the friction torque in the pivots due to the wt. of the car varies between the stationary torque and half the stationary torque, so that the minimum friction torque in motion available is 400/2 + 375 = 575 ins.lbs. Now with multi-plate friction in the pivots, we | ||