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).
Secret memorandum discussing various engine mounting schemes to address roughness, based on a telegram from 'R.' detailing tests with rigid and flexible feet.
| Identifier | WestWitteringFiles\T\January1929-February1929\ Scan002 | |
| Date | 1st May 1929 | |
| FROM E.{Mr Elliott - Chief Engineer} C. to [REDACTED] HS.{Lord Ernest Hives - Chair} DA.{Bernard Day - Chassis Design} PY. RM.{William Robotham - Chief Engineer} SECRET SS.{S. Smith} ENGINE MOUNTING. X7005 X738 [Handwritten and crossed out] We have this morning received your telegram as follows, via Royce Ltd. Manchester: "ELLIOTT PLEASE TEST AT ONCE RIGID FRONT FEET FLEXIBLE REAR "WITH ENGINE DAMPERS AT FLYWHEEL CASING OR REAR OF GEARBOX "AT LARGE RADIUS PREFERABLY UNDER FRAME TEMPORARY BUT RIGID- "TELEPHONE AND VISIT DERBY R.{Sir Henry Royce}" This is the scheme we advocated and HS.{Lord Ernest Hives - Chair} agreed to try when it was concluded that the engine was too rough with solid front feet and any degree of flexibility at rear obtainable with existing feet. It was proposed to use twoof our standard torque reaction dampers anchored to the flywheel casing and chassis frame. We do not know what progress has been made with this, but we have this morning (Saturday) mailed a scheme to Derby - LeC. 2634. - shewing these dampers arranged as per your telegram on back end of flywheel casing, and we shall telephone Derby on Monday morning, re. same. Attaching dampers effectively to the back end of the gearbox is not so easy, but DA.{Bernard Day - Chassis Design} is looking into this matter as we think this may be a very good position for damping. In testing SS.{S. Smith} with solid front and flexible rear feet, but no dampers, it was noted that although the engine was felt generally it also had periods of more intense roughness, and it was somewhat concluded that dampers at the rear would cure the periodic effects but not necessarily the general roughness. In view of this a second scheme was put forward just before leaving Derby as an alternative, to anchor the engine at all four corners to the frame with friction dampers, but use rubber mounting for both front and rear feet, the object being to make the engine into a friction cross to damp out the frame 'shimmy' and modify the roughness of the engine felt with the solid front mounting. We assume that RM.{William Robotham - Chief Engineer} will rig up the remaining SS.{S. Smith} chassis in Derby - e.g. 20-EX. with solid front feet and flexible rear, with dampers to LeC. 2634. The original of LeC. 2634. is attached to BY's copy of this note, and we will 'phone RM.{William Robotham - Chief Engineer} Mondaymorning. If required we will be in Derby as soon as this is ready for test. E.{Mr Elliott - Chief Engineer} | ||