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).
Proposals and effects of different spring lubrication methods, including the Bijur system and accumulators.
| Identifier | ExFiles\Box 27\1\ Scan064 | |
| Date | 14th February 1929 guessed | |
| - 2 - Apparently this only failed through defects in laying out the coils to the drip plugs, these pipes breaking after a time through relative movement. Proposal for Lubricating Present Springs. We feel that the correct method is to use a gaiter or not, as indicated by the experiments, but to use it only for protection of the spring, to keep water out. The oil feed should be part of the mechanism of the car, and apart from the gaiters. We thought that the spring plates should preferably not be drilled because of danger of breakage, particularly in torsion which throws the highest stress to the center of the spring leaf. However Mr. Allen tells me that on our older springs with a slot and bead there was no indication that the slot caused breakage. On the other hand 25% of our breakages were due to careless punching of the bead which caused actual tearing of the metal. It appears therefore that small oil holes drilled fairly near the end of each plate would not cause the spring to break, and the logical thing would then seem to be to feed the front spring from either shackle, and the inverted rear spring from the center-bolt, and drill holes near the tips to lead the oil from one leaf to the next. Effect on Bijur System. Mr. Bijur has pointed out that the addition of large drip plugs near the far ends of the central lubrication system will necessarily increase the pressure drop in the line and upset distribution. He would propose to overcome this by taking as direct a line as possible from the pump to these large drip plugs, and then using these points of large flow as "centers of distribution" from which pipes radiate to the points of lesser flow. This is an important minor point which I think will interest you. Use of "Accumulators". On February 1st I sent you some notes of the troubles we had met in the Bijur application, and enclosed prints of the Bijur automatic feed pump and "accumulator". (D-1120) Mr. Bijur points out that with the automatic system if the road springs are included in the system and the demand for oil increased say 100%, this is easily allowed for by increasing the stroke of the vacuum-operated pump to meet the demand. -continued- | ||