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).
Design changes to the automatic damper control for the P. 2. S. M. gearbox.
Identifier | ExFiles\Box 178\3\ img157 | |
Date | 5th May 1932 | |
ORIGINAL L. FROM DA.{Bernard Day - Chassis Design} C. to BG. Dr. HS.{Lord Ernest Hives - Chair} DA{Bernard Day - Chassis Design}1/W5.5.32. x7520. x7310. SHOCK DAMPERS - AUTOMATIC DAMPER CONTROL - P. 2. S. M.{Mr Moon / Mr Moore} GEARBOX. Herewith we send N. sch. 3468. shewing the arrangement of automatic control of the dampers in accordance with the speed of the car, as recently instructed by R.{Sir Henry Royce} In view of the nearness of R's return and also of the fact that we have had fairly precise instructions from him, we are sending this drawing simultaneously to him and Derby, telling R.{Sir Henry Royce} that this is so. We have departed from R's sketch in the following particulars:- (1) We have suggested the elimination of the reduction gear to the pump. This is because R.{Sir Henry Royce} has been under the impression that the servo travelled at a quarter engine speed, whereas actually it is one ninth engine speed. Under these circumstances an additional reduction seems unnecessary. The removal considerably simplifies the mechanism. (2) We have changed the angle at which the governor balls lie from approx: 30 to 45°. The reason for this is that at 45° it is much less important where the governor is set as the pressure on the ball valve is practically unaltered by considerable variations in the position of the governor balls. This is not the case at the 30° angle which would therefore require more careful setting. (3) On R's sketch the slot for dismounting the eccentric strap is shewn at right angles to the load. We have shewn it on top in line with the load. This is to enable us to assemble the eccentric in the box. We think that R's intention was to assemble the eccentric and strap while off the spindle, which permits of the slot being at right angles but does not lend itself to assembly inside the box. It is suggested that the load is so slight that the cutting away at the top of the eccentric strap will be unimportant. The maximum speed is approximately 300 RPM. (4) The pin conveying the pressure from the governor balls to the rod operating the ball valve has been passed through a large clearance hole instead of a slot drilled hole, the governor sleeve being prevented from turning by fitting the square of the shaft. The idea of this is to save the slot drilling. We also send N. sch. 3469 shewing an alternative method of retaining the oil in both the damper casing and the gearbox by means of R.{Sir Henry Royce} and L.H. threads. The object of this is to avoid the possibility of the loss of damper oil through the single thread shewn on N. sch. 3468. due to dripping from the casing, the single thread being arranged to prevent oil from the gearbox entering the damper reservoir. It will be noticed that we have found it necessary to move the handbrake somewhat, and to alter the bolting to the speedometer drive case. DA.{Bernard Day - Chassis Design} | ||