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).
Two revised designs for the 'A.C.' bye-pass filter mounting to address failures experienced during testing.
Identifier | ExFiles\Box 135\4\ scan0126 | |
Date | 9th April 1938 | |
1134- PY/MS. c. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/SwDL{Len H. Swindell} Files SWDL{Len H. Swindell} DA.{Bernard Day - Chassis Design}11/G.9.4.38. WRAITH 111. "A.C." BYE-PASS FILTER MOUNTING. Please receive herewith :- E.CD.597 Revised Mounting for A.C. Filter - Wraith 111 and Bentley 111. E.CD.599 Felt Lined Carrier for A.C. Filter - Wraith 111 and Bentley 111. The object of these designs is to eliminate the failure of the filters as experienced on the Wraith 111 test car in France, it being assumed that the cause of the failure was due to a high local pressure from the support saddle on the filter casing at points where the casing material had already been overstressed in the drawing operation during the process of manufacture. On E.CD.597 we have widened both the strap and the saddle, in order to give increased stability for the filter and also to spread the holding load on the casing and bring it further away from the casing joint seam. E.CD.599 shows the existing fixing with a hard felt lining added in the saddle piece, we are rather afraid that the felt lining will not hold the filter rigidly enough, and the filter movement may be sufficient to cause the oil pipes connected to filter to work harden and fracture. On the model we viewed of the filter support, the radius of the saddle did not correspond with the radius of the filter casing. Care should be taken that a reasonable bedding should be obtained along the whole of the saddle, otherwise high pressure spots are bound to be present. Will you please detail and instruct the necessary parts for these experiments. It should be noted that if one of these designs is accepted for standardisation on the Wraith 111 engine, the same fixing should be used on the following engines also :- (1). Bentley 111. (2). Bentley 50 (Cast iron engine). (3). Phantom 111 with A.C. Bye-pass filter. DA.{Bernard Day - Chassis Design} | ||