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).
Vacuum pump components and airscrew development research at Pratt & Whitney.
| Identifier | ExFiles\Box 27\3\ Scan228 | |
| Date | 15th May 1939 guessed | |
| 22. The bakelite blades used in the Eclipse vacuum pumps appeared to be standing up to the duty extremly well. Developments are in hand on improved oil metering. On the general question of vacuum pump lubrication, no firm attempts to recover the oil used, preferring to lose it rather than to risk introducing vacuum pump detritus into the engine system. Pesco fuel pumps are held in high esteem by the engine companies. Pesco claim to be the largest suppliers of fuel pumps and large vacuum pumps to the Army and Navy. They have recently been incorporated in the Borg-Warner organisation. Airscrews During the visit to Pratt & Whitney, a short time was spent with Mr.Frank Caldwell in the new plant of the Hamilton Standard Propellor Division, which had only recently been occupied. The new building is close to the original Pratt & Whitney building, and the move has given the engine firm room to expand. Present production is 100 airscrews per week, including a fair number of hydromatics. There was time only for a short discussion, and the high spots are given below. A great deal of research work is proceeding on airscrew vibration. 35,000 records have already been taken with the carbon-pile extensometer, and there is a staff of 20 technicians dealing with the problem. The 'gigolo' machine, which was used formerly to break blades, has been dropped and all work is now done with pneumatically-driven out of balance rotors. A three-bladed airscrew which had each blade bent at the tip through an angle of about 30° was being vibrated - "just an experiment" said Mr.Caldwell. Mr.Caldwell does not like the Schwatz blade, but he is experimenting with blades with dural roots, having mould.d forms built-up on them. He thinks that the solution to lighter airscrews will | ||