any of the gears in an epicyclic train surrounding and engaging with the sun gear.
Origin of planet gear
First recorded in 1915–20
Also called planet wheel.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for planet wheel
any one of the wheels of an epicyclic gear train that orbits the central axis of the train
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012