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).
Comparative analysis of the efficiency and performance of various electric motor designs.
| Identifier | WestWitteringFiles\T\2July1929-December1929\ Scan023 | |
| Date | 1st July 1929 guessed | |
| -6- contd. torque at heavy current due to saturation as shown by Øs curve. Poor mechanical efficiency. 3. FIRST NO.2 SCHEME 5" DIAMETER SLIDING ARMATURE SEQUENCE MOTOR (K) WITH RAPIDLY TAPERING ARMATURE AND 45 SECTIONS. Maximum overall efficiency is .50 and occurs at 85 amperes, the corresponding electrical and mechanical efficiencies being .75 and .67 respectively. Poor Øs curve and stalling torque. Fair mechanical efficiency. Still on chassis 9-EX. 4. PRE WAR R.{Sir Henry Royce} BOSCH S.45. 41 SECTION ARMATURE 5.900" DIAMETER MOTOR WITH 6 : 1 EPICYCLIC REDUCTION GEAR. Maximum overall efficiency is .74 and occurs at about 90 amperes, the corresponding electrical and mechanical efficiencies being .82 and .90. Øs curve shows absence of saturation effect. Note high mechanical efficiency as evidenced by closeness of Tr{Capt. F. W. Turner - Finance} and Ts curves and as in the case also of the R.R. epicyclic gear motor. 5. POST-WAR R.{Sir Henry Royce} BOSCH 31 SECTION SLIDING ARMATURE 4.920" DIAMETER MOTOR. Maximum overall efficiency is .52 and occurs at 140 amperes, the corresponding electrical and mechanical efficiencies being .735 and .705. Øs curve shows saturation, and stalling torque is poor. Electrical efficiency is high but mechanical efficiency is low. Does not appear to be a well electrically proportioned motor, the number of armature conductors and field turns being too low. | ||