capstan vs driving shaft

capstan

noun
  • A vertical cylindrical machine that revolves on a spindle, used to apply force to ropes, cables, etc. It is typically surmounted by a drumhead with sockets for levers used to turn it. 

  • A rotating spindle used to move recording tape through the mechanism of a tape recorder. 

driving shaft

noun
  • A shaft from a driving wheel communicating motion to machinery. 

How often have the words capstan and driving shaft occurred in a corpus of books? (source: Google Ngram Viewer )