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).
Spring load and coefficient of friction for a servo linkage.
| Identifier | WestWitteringFiles\Q\January1927-March1927\ 137 | |
| Date | 17th March 1927 | |
| TO HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer}) FROM DA.{Bernard Day - Chassis Design} DA{Bernard Day - Chassis Design}2/M17.3.27. FRICTION OF EAC. 7. SERVO LINKAGE. X7370 With reference to HS{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}3/LG24227., the spring called for on our design is 410 lbs. which, with a co-efficient of friction of .150, should give 29 lbs. at the ends of the links. We should have thought this co-efficient of friction of .150 was a reasonable one. The load asked for is 25 lbs. and therefore it seems to us that we have given it with the present spring. The load of 16 lbs. which is said to be obtained represents a co-efficient of friction of .083 which seems extraordinarily low. Would it be possible to verify these figures again. If they are confirmed we can get a spring into the space available which has 1 1/2 coils .275 dia. wire, giving a load of 544 lbs., which, with a co-efficient of friction of less than .1, would give you 25 lbs. on the ends of the links, but we do not wish to use this heavy spring unless it is necessary. DA.{Bernard Day - Chassis Design} | ||