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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).
Calculations for motor armature slot and conductor dimensions.

Identifier  ExFiles\Box 64\2\  scan0086
Date  22th June 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
conductor = .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)
= kx45 .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.
  
  


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