Rolls-Royce Archives
         « Prev  Box Series  Next »        

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.
  
  
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).


Copyright Sustain 2026, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙