Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Letter discussing damper orifice regulation and ride quality, including a graph of oil pressure versus velocity.

Identifier  ExFiles\Box 170\2\  img102
Date  18th October 1931
  
Detroit.
October 18/31

Dear RW,
I have not replied to yours of Sep 15 before, because the matter was not fully worked out.
The trouble with orifice-regulation of dampers appears to be that the freer settings give an unstable ride.
Suppose one draws a diagram of oil-pressure against oil-velocity thus:-

[Graph showing Oil Pressure vs{J. Vickers} Oil Velocity]
Graph Labels:
OIL PRESSURE
OIL VELOCITY
no orifice
Quick build up
slow build-up
A, B, C effects of increasing orifice
1, 2, 3, 4, 5 successive positions of spring control.
Oil velocity for usual axle movements
Oil velocity for usual car movements

Opening orifice to regulate the shocks does not necessarily give a smoother ride, because while the car movements are not sufficiently damped, the axle movements shake the car almost as much as without orifice.
In fact, in the case of lubricated springs and
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙