pulley vs trunnion

pulley

noun
  • One of the simple machines; a sheave, a wheel with a grooved rim, in which a pulled rope or chain lifts an object (more useful when two or more pulleys are used together, as in a block and tackle arrangement, such that a small force moving through a greater distance can exert a larger force through a smaller distance). 

verb
  • To raise or lift by means of a pulley. 

trunnion

noun
  • A similar rotational bearing comprising a rotating arc or ring sliding in the groove of a stationary arc, used in machinery to allow a workpiece to be moved relative to a fixed tool. 

  • A similar rotational bearing used in automotive suspensions. 

  • A shaft, held by a bearing, at each end or side of a rotatable object. 

  • One of the short stubby bearings on either side of a cannon; a gudgeon. 

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