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).
Page of calculations for armature slot dimensions, conductor area, and space efficiency for a motor.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 200 | |
| Date | 31th March 1927 guessed | |
| -4- Contd. Depth of slot must not exceed = √A/2π = √.222 = .471" Take slot depth = .390" Then slot width = .080" Width of slot for insulation = .035" (as on 6"motor) Therefore width of conductor = .045" Depth of slot for insulation = .080" " " " clearance = .020" Hence depth of slot for conductors. = .290" " " " conductor. = .145" Space efficiency = (.290 x .045) / (.390 x .080) = 41.8% (excluding rounding of corners of conductors) C.S. area of conductor (excluding rounding) = .145 x .045 = .00653 sq.inch. Armature dia. = 3.100" Pitch of teeth at circumference = (3.100 x π) / 45 = .216 Width of tooth at top = .136" Bottom of tooth is at 3.100 - 2 x .350" dia., i.e. at 2.400" dia. Contd. | ||